U.S. patent application number 10/203075 was filed with the patent office on 2003-06-19 for method for functionalising a double bond.
Invention is credited to Roques, Nicolas.
Application Number | 20030114721 10/203075 |
Document ID | / |
Family ID | 8846927 |
Filed Date | 2003-06-19 |
United States Patent
Application |
20030114721 |
Kind Code |
A1 |
Roques, Nicolas |
June 19, 2003 |
Method for functionalising a double bond
Abstract
The invention concerns a method for functionalizing a double
bond and, more particularly, a double bond bearing a metalloid
atom. Said functionalization is produced by the action of
perhalogenated sulphonyl chloride on the carbon bearing sulphur in
the presence of a free radical initiator, preferably by homolytic
cleavage. The invention is useful in organic synthesis.
Inventors: |
Roques, Nicolas; (Lyon,
FR) |
Correspondence
Address: |
Kevin E McVeigh
Intellectual Property Dept
Rhodia
259 Prospect Plains Road CN 7500
Cranbury
NJ
08512-7500
US
|
Family ID: |
8846927 |
Appl. No.: |
10/203075 |
Filed: |
August 6, 2002 |
PCT Filed: |
February 12, 2001 |
PCT NO: |
PCT/FR01/00364 |
Current U.S.
Class: |
570/232 ;
568/28 |
Current CPC
Class: |
C07B 37/02 20130101;
C07C 43/16 20130101; C07C 41/30 20130101; C07B 39/00 20130101; C07C
67/293 20130101; C07C 31/34 20130101; C07C 41/30 20130101 |
Class at
Publication: |
570/232 ;
568/28 |
International
Class: |
C07C 017/08 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 11, 2000 |
FR |
00/01744 |
Claims
1. A process for functionalizing a double bond corresponding to
formula I: 16in which R.sub.1, R.sub.2 and R.sub.3, which may be
identical or different, are chosen from hydrogen and hydrocarbyls
attached to said double bond via an sp.sup.3 carbon; in which z is
chosen from: halogens, advantageously chlorine and fluorine;
residues such that ZH is an oxygenated acid; radicals of formula
(CHR').sub.m- with chosen from halogens; and radicals of formula
(CHR').sub.m--Y(O).sub.q--R.sub.4 in which Y is a chalcogen,
advantageously a light chalcogen; q is zero or an integer not more
than 3, advantageously not more than 2 and preferably not more than
1, with the condition that when Y is oxygen, q is equal to zero; R'
represents a hydrocarbyl, advantageously of not more than four
carbons, or preferably a hydrogen; m is equal to 1 or preferably to
zero; and R.sub.4 is chosen from a hydrocarbyl or silyl group; by
the action of sulfonyl chloride perhalogenated on the
sulfur-bearing carbon (of the sulfonyl function) in the presence of
a free-radical initiator, preferably by homolytic cleavage.
2. The process as claimed in claim 1, characterized in that Z is of
the nature Y--R.sub.4 with Y being a light chalcogen.
3. The process as claimed in claims 1 and 2, characterized in that
R.sub.4 is an electron-withdrawing group.
4. The process as claimed in claims 1 to 3, characterized in that
the free-radical initiator is an initiator by homolytic
cleavage.
5. A process as claimed in claims 1 to 4, characterized in that the
perhalogenated sulfonyl chloride corresponds to the formula
R.sub.f--SO.sub.2--Cl in which Rf corresponds to the formula:
EWG-(CX.sub.2).sub.p--in which the radicals X, which may be similar
or different, represent a chlorine, a fluorine or a radical of
formula C.sub.nF.sub.2n+1 with n being an integer not more than 5
and preferably not more than 2, with the condition that at least
one of the radicals X is fluorine; in which p represents an integer
not more than 2; in which EWG represents an electron-withdrawing
group, the possible functions of which are inert under the reaction
conditions, advantageously fluorine or a perfluoro residue of
formula C.sub.nF.sub.2n+1, with n being an integer not more than 8
and advantageously not more than 5, the total number of carbon in
R.sub.f advantageously being between 1 and 15 and preferably
between 1 and 10.
6. The process as claimed in claims 1 to 5, characterized in that
R.sub.f contains not more than 6 carbon atoms, advantageously not
more than 5 and preferably not more than 3.
7. The process as claimed in claims 1 to 6, characterized in that Y
is oxygen.
8. The process as claimed in claims 1 to 7, characterized in that
R.sub.4 is an acyl of not more than 15 carbon atoms and preferably
not more than 10 carbon atoms.
9. A compound of formula (II): 17with R.sub.1, R.sub.2, Z and Rf
being chosen from the same values (and with the same preferences)
as above, but with the following additional conditions: with
R.sub.1 and R.sub.2 chosen from hydrogen and hydrocarbyl radicals,
with the condition that one of the radicals R.sub.1 or R.sub.2 at
least is equal to H, and advantageously both of them; with Z chosen
from radicals of formula (CHR').sub.m--Y--R.sub.4 in which R.sub.4Y
is such that R.sub.4YH is an oxygenated acid, the possible aromatic
nucleus (nuclei) being separated from said double bond by at least
two atoms of sp.sup.3 hybridization (in the case of Z, an oxygen
atom and at least one carbon atom, advantageously at least two
sp.sup.3 carbon atoms; in the other cases, at least two sp.sup.3
carbon atoms); the total carbon number of the molecule being at
least equal to (6-m) and not more than 30. Use of a compound of
formula (II) in which m is equal to 1, to prepare a
3-perfluoroalkyl-1,2-epoxypropane:
10. A compound of formula (III) 18
11. The use of compounds of formula (III) to prepare a
3-perfluoroalkyl-1,2-epoxypropane.
Description
[0001] The present invention relates to a process for
functionalizing a double bond, and more particularly a double bond
bearing a metalloid atom. More particularly, the present invention
is directed toward adding to a double bond, on the one hand, and to
one of the atoms a halogen atom and, on the other hand, to the
other carbon-based radical whose carbon atom is perhalogenated.
[0002] Compounds comprising perhalogenated and especially perfluoro
carbon atoms play an increasingly important role in derivatives
with biological activity, whether this biological activity is
exerted in the animal kingdom or in the plant kingdom.
[0003] The synthesis or grafting of these perhalogenated and more
preferentially perfluoro compounds is often difficult and requires
expensive means.
[0004] Among the techniques that have been proposed is the one
consisting in subjecting a double bond to the action of a sulfonyl
halide. In particular, the action of trifluoromethanesulfonyl
bromide has already been described in the Bulletin de la Societe
Chimique de France, No. 6, 1986, from page 881 to page 884.
[0005] However, sulfonyl bromide is difficult and expensive to
handle, especially on account of the high instability of this
bromide. In addition, the bromide, like the chloride, is a powerful
oxidizing agent which can modify the capacities for survival of the
products obtained during this addition. The bromide ions formed
during the reaction that react with the residual bromide can lead
to bromine, which is then a source of further spurious
reactions.
[0006] Trifluoromethanesulfonyl chloride, which is occasionally
known as triflyl chloride, is significantly less reactive than the
bromide; thus, it has been attempted to use very specific ruthenium
complexes (Ru(P.quadrature..sub.3)Cl.sub.2) to catalyze the
addition to double bonds.
[0007] This addition appears to be relatively versatile, but the
reactions are often difficult to reproduce and the results appear
to be somewhat erratic.
[0008] It has also been proposed, in the case of double bonds
bearing a silicon atom, to use free-radical generators such as
tert-butyl peroxide.
[0009] One of the major risks of this technique lies in the fact
that double bonds, under the action of free radicals, have a
tendency to polymerize and not to lead to the addition reaction.
Another risk is an oxidation with a chlorine according to a
mechanism of positive chlorine type.
[0010] Thus, in the course of the study that led to the present
invention, it has been possible to show that the action of sulfonyl
chlorides on double bonds activated with an aromatic nucleus leads
essentially to polymerization reactions rather than addition
reactions.
[0011] In addition, certain double bonds, especially those that
present major advantages for manufacturing synthons, are often not
reactive enough to form the desired addition compounds.
[0012] It is thus seen that the decomposition of sulfonyl chlorides
that are perhalogenated on the sulfur-bearing carbon of the
sulfonyl bonds does not give an addition reaction on a double bond
with good results, except in an extremely limited number of
already-functionalized products.
[0013] Accordingly, one of the aims of the present invention is to
define a family of compounds bearing already-functionalized double
bonds, that can give acceptable addition yields with a technique of
decomposition of sulfonyl chloride initiated by free radicals.
[0014] Another aim of the present invention is to provide an
optimization of the operating conditions for this novel family of
compounds.
[0015] Another aim of the present invention is to provide a process
that does not require expensive catalysts such as those based on
metals from column VIII, especially of the platinum mine, and in
particular ruthenium.
[0016] Another aim of the present invention is to provide a process
in which ruthenium, especially in the form coordinated with
phosphines and especially aromatic phosphines, is present in an
amount such that the [Ru]/[sulfonyl chloride perhalogenated on the
sulfur-bearing carbon] molar ratio is not more than 1,
advantageously 0.1 and preferably 0.01. It is even preferable for
it not to be present.
[0017] Another aim of the present invention is to provide a process
in which the platinum mine metals are present in an amount such
that the [sum of the platinum mine metals]/[sulfonyl chloride
perhalogenated on the sulfur-bearing carbon] molar ratio is not
more than 1, advantageously 0.1 and preferably 0.01. It is even
preferable that they are not present.
[0018] Another aim of the present invention is to provide a process
in which the metals from column VIII are present in an amount such
that the [sum of the metals from column VIII]/[sulfonyl chloride
perhalogenated on the sulfur-bearing carbon] molar ratio is not
more than 1, advantageously 0.16 and preferably 0.0. It is even
preferable for them not to be present.
[0019] Another aim of the present invention is to provide novel
intermediates allowing novel synthetic routes.
[0020] The Periodic Table of the Elements used in the present
patent application is that of the supplement to the Bulletin de la
Socit Chimique de France, January 1966, No. 1.
[0021] It may be useful to recall that the expression "identical or
different" is used to indicate that the substituents under
consideration may or may not be the same.
[0022] These aims and others which will become apparent hereinbelow
are achieved by means of a process for functionalizing a double
bond corresponding to formula I: 1
[0023] in which R.sub.1, R.sub.2 and R.sub.3, which may be
identical or different, are chosen from hydrogen and hydrocarbyls
attached to said double bond via a carbon of Sp.sup.3
hybridization;
[0024] in which Z is chosen from:
[0025] halogens, advantageously chlorine and fluorine;
[0026] residues such that ZH is an oxygenated acid;
[0027] radicals of formula (CHR').sub.m- with chosen from
halogens;
[0028] and radicals of formula (CHR').sub.m--Y(O).sub.q--R.sub.4 in
which
[0029] Y is a chalcogen, advantageously a light chalcogen;
[0030] q is zero or an integer not more than 3, advantageously not
more than 2 and preferably not more than 1, with the condition that
when Y is oxygen, q is equal to zero;
[0031] R' represents a hydrocarbyl, advantageously of not more than
four carbons, or preferably a hydrogen;
[0032] m is equal to 1 or preferably to zero;
[0033] and R.sub.4 is chosen from a hydrocarbyl or silyl group;
[0034] by the action of sulfonyl chloride perhalogenated on the
sulfur-bearing carbon (of the sulfonyl function) in the presence of
a free-radical initiator, preferably by homolytic cleavage.
[0035] The expression "perhalogenated carbon" should be understood
as meaning a carbon of sp.sup.3 nature optionally substituted with
not more than two, and advantageously not more than one,
electron-withdrawing group(s), and bearing no hydrogen, all the
other atoms being halogens. It is preferable for these halogens
borne by said perhalogenated carbon all to be chlorine or fluorine
and preferably all fluorine.
[0036] It is important that the radicals R.sub.1, R.sub.3 and
R.sub.2, when they are hydrocarbyls (i.e. comprising hydrogen and
carbon, but possibly comprising other atoms), are attached to the
double bond via one of their sp.sup.3 carbons, otherwise the
reactivity toward the sulfonyl chloride is greatly affected
thereby. In particular, the presence of an aromatic directly
attached to the double bond plays an extremely unfavorable role. It
is also recommended to avoid carbon atoms that are both allylic and
benzylic. More generally, even when they are not conjugated with
said double bond, the presence of an aromatic in the molecule is
unfavorable. Thus, the presence of an aromatic in Z, especially
when ZH is an oxygenated acid, is unfavorable especially when an
aromatic nucleus is separated from a carbon of said double bond by
less than two atoms of sp.sup.3 hybridization (oxygen or carbon,
preferably at least two sp.sup.3 carbons). It should be noted that
there is overlap between the definition of Z,
Z.dbd.(CHR').sub.m--Y(O).sub.q--R- .sub.4 and that which indicates
that Z is such that ZH is an oxygenated acid, especially when m is
equal to zero, when q is equal to zero, when Y is oxygen and
R.sub.4 is a hydrocarbon radical attached to Y via an
electron-withdrawing function such as, especially, carbonyl
(--CO--), carbonate (--CO--O--), sulfonyl (SO.sub.2), sulfoxide
(--SO--), sulfate (--SO.sub.3--), phosphate [P(.dbd.O)(--O--)O--],
phosphonate [P(.dbd.O)(--O--)--] and phosphinate
[P(.dbd.O)(--)--].
[0037] For reasons of steric bulk, it is recommended to choose the
radicals R.sub.1, R.sub.3 and R.sub.2 such that at least one and
preferably two of these three radicals is hydrogen. It is also
preferable that neither R.sub.1 nor R.sub.2 is tertiary. It is also
preferable that at least one, and even both, of the radicals
R.sub.1 and R.sub.2 are hydrogen.
[0038] It is preferable that the initiator generating the free
radicals releases these radicals after a homolytic cleavage, i.e. a
cleavage taking place between two atoms of the same element and
generating an electron radical on each of the two atoms. This
cleavage may be actinic, catalytic or, preferably, thermal.
[0039] The cleavage may also be heterolytic when systems are used
involving metals that have two valency states (iron or copper) with
peroxides and especially hydroperoxides.
[0040] Examples of preferred initiators that should be mentioned
include various peroxides, preferably symmetrical, and various azo
compounds, such as azobisisobutyronitrile (reference may be made
especially to the "Polymer Handbook"). Among the peroxides, mention
may be made of alkyl peroxides and especially tert-alkyl peroxides,
and acyl peroxides, especially alkanoyl peroxides, that are
preferably symmetrical.
[0041] The acyl peroxides that may be used are preferably peroxides
whose acyls are of low molecular weight, i.e. their carbon number
is not more than 10, and preferably not more than 6 when they are
aliphatic, but it is preferable to use acyl peroxides of aromatic
nature, for instance benzoyl peroxide.
[0042] The free-radical initiator is advantageously not more than
0.2 times the molar amount of the sulfonyl chloride, preferably not
more than 0.1 times, the optimum zone being between 1% and 8% of
the amount of sulfonyl chloride. The reaction is advantageously
conducted such that the release of the free radicals takes place
gradually. A good technique for achieving this objective consists
in adding the initiator, i.e. the free-radical generator, slowly
and gradually. Another technique consists in using a temperature
that allows the release of the free radicals to be controlled.
[0043] The reaction temperature is regulated such that it is
between ambient temperature and 150.degree. C., preferably between
50 and 120.degree. C. and more preferentially between 60 and
100.degree. C.
[0044] It should be noted that, for certain substrates, the
reaction does not need an initiator, especially for substrates
whose double bond bears a chalcogen, usually an oxygen. However,
the use of a free-radical generator still improves the reaction
yield.
[0045] The amount of substrate relative to the sulfonyl chloride is
about once the molar amount. However, to satisfy specific problems,
it is possible to depart considerably from this value which
corresponds to the stoichiometric value as defined by the following
reaction: 2
[0046] In particular, when there is a large risk of polymerization,
a smaller amount of compounds bearing a double bond may be used
relative to the amount of sulfonyl chloride. Thus, it is possible
to vary very widely the ratio between the substrate bearing the
double bond and the sulfonyl chloride. However, in the majority of
cases, the ratio is of the order of 1.+-.0.5.
[0047] The pressure may vary within large proportions but it is
preferable to work at an autogenous pressure or at atmospheric
pressure.
[0048] Although its presence is not necessary, it is possible to
use a solvent. The solvents that may be used are solvents that are
inert toward sulfonyl chloride and that do not constitute
free-radical traps.
[0049] Mention may thus be made of the hydrocarbons and halogenated
derivatives that are usually used in free-radical chlorination
reactions.
[0050] More specifically, alkanes with a suitable boiling point,
i.e. whose boiling point is at least equal to the temperature at
which it is desired to work; petroleum fractions; aromatic chloro
derivatives, are all entirely acceptable.
[0051] The sulfonyl chlorides that are preferred are those
corresponding to the formula R.sub.f--SO.sub.2--Cl in which R.sub.f
corresponds to formula (IV):
EWG-(CX.sub.2).sub.p--
[0052] in which:
[0053] the radicals X, which may be similar (i.e. they are
identical) or different, represent a chlorine, a fluorine or a
radical of formula C.sub.nF.sub.2n+1 with n being an integer not
more than 5 and preferably not more than 2, with the condition that
at least one of the radicals X is fluorine; when p is equal to
1,
[0054] EWG is an electron-withdrawing group (that is to say that
the Hammett constant sigma p is >0, advantageously at least
equal to 0.2), otherwise it may be any radical, which is preferably
inert, and advantageously an electron-withdrawing group (cf.
preceding lines);
[0055] p is a positive integer, i.e. it cannot comprise the value
0.
[0056] EWG is advantageously fluorine, especially when p is less
than or equal to 2.
[0057] The radicals X are advantageously all fluorine, especially
when p is less than or equal to 2.
[0058] Another value of EWG (electron-withdrawing group) is when it
equals chlorine; in this case, EWG is a chlorine.
[0059] p represents an integer advantageously not more than 4 and
preferably not more than 2;
[0060] EWG advantageously represents an electron-withdrawing group
whose optional functions are inert under the reaction conditions,
advantageously fluorine or a perfluoro residue of formula
C.sub.nF.sub.2n+1, with n being an integer not more than 8 and
advantageously not more than 5.
[0061] The total carbon number of Rf is advantageously between 1
and 15 and preferably between 1 and 10.
[0062] It is advantageous that Rf should be of formula
C.sub.rF.sub.2r+1 with r being an integer not more than 15 and
advantageously between 1 and 10.
[0063] The present invention is particularly advantageous for
radicals R.sub.f of low molecular weight, i.e. those that are
relatively volatile (with a boiling point at atmospheric pressure
of not more than 100.degree. C.). The technique is particularly
advantageous for radicals R.sub.f containing a radical with an odd
number of carbons, and particular mention should be made for
radicals R.sub.f of C.sub.1, C.sub.2 and C.sub.3.
[0064] Radicals R.sub.f higher than C.sub.6 are less
advantageous.
[0065] The compounds that give the most advantageous results are
those in which Z is of structure Y--R.sub.4 with Y being a
chalcogen, preferably a light chalcogen, i.e. sulfur or oxygen and
more particularly the latter.
[0066] R.sub.4 is a hydrocarbyl group, i.e. a group containing
hydrogen and carbon. These hydrocarbyl groups may be alkyl (i.e. an
alcohol residue of which the hydroxyl function is ignored), an aryl
or an oxygenated acid residue (i.e. a residue whose acidic hydrogen
is borne by an oxygen) from which an OH function has been removed.
In this latter group, mention may be made of acyls, phosphoryls,
phosphonyls, phosphinyls and sulfonyls. The acids
R.sub.4Y(O).sub.q-- advantageously have a pKa of not more than 10,
preferably not more than 8 and more preferentially not more than 6.
Acids with a Hammett constant that is greater than or equal to that
of perfluoroalkane-sulfonic acids, and especially triflic acid, are
not preferred.
[0067] The group R.sub.4 is advantageously an electron-withdrawing
group of the acyl type.
[0068] It is preferable for the molecule bearing the double bond
not to contain a strongly reductive function, or a nucleophilic
function capable of reacting with the sulfonyl chloride.
[0069] The total carbon number of the substrate of formula I is
generally not more than 50 (one significant figure) and better
still not more than 30. In particular, when Rf is of the type
CX.sub.3(CX.sub.2).sub.s, the presence of halogens heavier than
fluorine at the other end of the chain Rf liable to give spurious
reactions, especially when the chain Rf is short (s less than or
equal to 5 and, even, less than or equal to 4). As has been stated
previously, another aim of the present invention is that of
providing reaction intermediates that allow novel routes of
access.
[0070] This aim is achieved by means of compounds corresponding to
the formula: 3
[0071] with R.sub.1, R.sub.2, Z and Rf being chosen from the same
values (and with the same preferences) as above, but with the
following additional conditions:
[0072] with R.sub.1 and R.sub.2 chosen from hydrogen and
hydrocarbyl radicals, with the condition that one of the radicals
R.sub.1 or R.sub.2 at least is equal to H, and advantageously both
of them;
[0073] with Z chosen from radicals of formula
(CHR').sub.m--Y--R.sub.4 in which R.sub.4--Y is such that R.sub.4YH
is an oxygenated acid,
[0074] the possible aromatic nucleus (nuclei) being separated from
said double bond by at least two atoms of sp.sup.3 hybridization
(in the case of Z, an oxygen atom and at least one carbon atom,
advantageously at least two sp.sup.3 carbon atoms; in the other
cases, at least two sp.sup.3 carbon atoms);
[0075] the total carbon number of the molecule being at least equal
to (6-m) and not more than 30, and advantageously in which:
[0076] Y is a chalcogen, advantageously a light chalcogen,
preferably oxygen;
[0077] R' represents a hydrocarbyl, advantageously of not more than
four carbons, or preferably a hydrogen;
[0078] m is equal to 1 or, preferably, to zero;
[0079] and R.sub.4 is chosen from hydrocarbyl groups,
advantageously from acyls.
[0080] It is advantageous for Rf to be of formula C.sub.rF.sub.2r+1
with r being an integer not more than 15, advantageously between 1
and 10 and preferably not more than 4.
[0081] For steric reasons, it is preferable for said acid
R.sub.4--YH not to comprise any branching alpha or beta to the atom
bearing the acidic proton, in general oxygen; thus, for example, in
the case of a carboxylic acid, the atom bearing the carboxylic
function, which is beta to the oxygen bearing the proton, is
advantageously neither tertiary nor even secondary, nor does it
correspond to the branching of an aromatic nucleus.
[0082] One subfamily of the above compounds is particularly novel,
namely the family in which m is equal to zero; when R.sub.3 is
other than H, the compounds are highly reactive [lacuna]
constitutes only reaction intermediates but remains identifiable,
especially at low temperature by fluorine-19 NMR. When R.sub.3 is
hydrogen, these compounds are surprisingly stable. These two
subfamilies decompose or are hydrolyzed to carbonyl, aldehyde or
ketone derivatives, see the examples. This subfamily may thus be
used to synthesize by hydrolysis, for example acid hydrolysis,
aldehydes or ketones and derivatives thereof. A subsequent
oxidation, which is known per se, of the aldehydes gives the
corresponding acids.
[0083] Another advantageous subfamily lies in the alcohol and the
corresponding esters in which m is equal to one and Y is oxygen and
in which, advantageously, R.sub.3 is H.
[0084] The alcohol is readily synthesized by alcoholysis of the
corresponding ester, without touching the chlorine borne by the
carbon atom adjacent to that bearing the ester function and then
the alcohol: 4
[0085] The alcohol or ester readily lead, especially under the
action of strong base (sodium hydroxide, potassium hydroxide or
quaternary ammonium hydroxide), the associated acid of which has a
pKa at least equal to 12 and advantageously to 13, to epoxides:
5
[0086] See the examples below.
[0087] The epoxides Rf--CHR.sub.1CR'(O)CH.sub.2 are important
organic intermediates given the importance of
"perfluoroalkylpropylene oxides and related compounds" in
application on account of their common properties:
[0088] polymerization catalysts,
[0089] urethane-fluoropolyether acrylate copolymers,
[0090] treatment of metal surfaces,
[0091] transparent materials,
[0092] hydrophobic coatings,
[0093] cosmetics.
[0094] As has been stated previously, for reasons of ease of
synthesis according to the invention and for reasons of stability,
it is desirable for Rf not to bear in the omega position (i.e. at
the other end of the chain) of the longest chain, a halogen heavier
than fluorine (i.e. chlorine, bromine or iodine).
[0095] The nonlimiting examples that follow illustrate the
invention.
EXAMPLE 1 (COMPARATIVE)
[0096] Action of trifluoromethanesulfonyl chloride on enol ethers
and esters in the presence of ruthenium activated with
triphenylphosphine (for the operating conditions, see Kamigata et
al., J. Chem. Soc. Perkin Trans., 1991, page 631, left-hand
column).
1 Substrate .theta..degree. C. T(h) DC %.sup.(b)(1) DC %.sup.(a) RY
%.sup.(b) Comments 6 100.degree. C. 24.5 100 nd.sup.(c) 0 -
Formation with RY =91.5% CF.sub.3SO.sub.2Et (characterization by
.sup.19F NMR and GC/MS). - Detection by GC/MS of by products
derived from (4): --CICH.sub.2CH.sub.2CO.sub.2Et
--CH.sub.3CO.sub.2Et 7 100.degree. C. 17.5 40 68 0 Detection by
GC/MS analysis of many decomposition products of
CH.sub.2.dbd.CHOCOC.sub.9H.sub.19: E.g.: C.sub.9H.sub.19CO.sub.2H
120.degree. C. 16 38 87.5 0 8 100.degree. C. 16 49 100 0 Detection
by GC/MS analysis of many decomposition products of
CH.sub.2.dbd.CHOC.sub.12H.sub.25: --C.sub.12H.sub.25OH (majority)
--C.sub.11H.sub.23CHO --C.sub.11H.sub.23COCF.sub.3 .sup.(a)GC assay
with internal standard .sup.(b).sup.19F NMR assay with internal
standard .sup.(c)not determined (&) .sup.(1)relative to the
sulfonyl chloride
EXAMPLE 2
[0097] Action on Various Vinyl Ethers
[0098] The initiator (0.376 mmol), the alkene (9.4 mmol) then
triflyl chloride (9.4 mmol) are successively introduced into a 60
mm Schott tube at 20.degree. C. The reaction is that indicated in
the general equation of the description with R.sub.1, R.sub.2,
R.sub.3.dbd.H.
2 Sub- Sub- DC RY Test (a) strate R Initiator t(h) strate %.sup.(b)
%.sup.(b) RON 5 OCOC.sub.9H.sub.19 (PhCO.sub.2).sub.2 13.5 1/1 82
41 240B BJ 540A OCOC.sub.9H.sub.19 (PhCO.sub.2).sub.2 7 1/1 77 45
BJ 544B OCOC.sub.9H.sub.19 AIBN 17 1/1.2 76.5 50 BJ 545A
OCOC.sub.9H.sub.19 AIBN 7 1/1.2 75.5 50 BOA 137 (12) OCOCH.sub.3
AIBN 7 1/1 82 52.5 BOA 9 (13) (CH.sub.2).sub.7CH.sub.3 AIBN 7 1/1.1
91 77.5
[0099] The addition products were identified by fluorine-19 NMR and
by gas chromatography coupled to a mass spectrograph.
[0100] The reaction was performed at 90.degree. C. and, at this
temperature, the reaction is complete, or at the very least has
ended, after 7 hours.
[0101] Contrary to the rutheniumtriphenylphosphine chloride system,
free-radical initiators allow the addition of trifluoromethyl, on
the one hand, and of chloride, on the other hand, to the double
bond of enol esters.
EXAMPLE 3
[0102] Study of the Role of the Amount of Free-Radical
Initiators
[0103] One equivalent of triflyl chloride, AIBN in variable
proportions and 1.2 equivalents of vinyl laurate are successively
introduced into a 60-ml Schott tube, the reaction mixture is then
maintained at 90.degree. C. for 7 hours while the solution is
stirred on a heating block.
[0104] The crude reaction mixture is analyzed by gas chromatography
and fluorine-19 NMR.
3 Mol % initiator DC %.sup.(b) DC %.sup.(c) RY %.sup.(b) 0 70 57 25
1 77.2 -- 43 4 84 86.5 56 6 85 95 54
EXAMPLE 4 (COMPARATIVE)
[0105] Influence of the Nature of the Triflyl Halide, Reaction with
Perfluorobutanesulfonic Fluorides
[0106] Under conditions similar to the previous test,
perfluorobutanesulfonic fluoride is tested in place of the triflyl
chloride.
4 Substrate R DC %.sup.(b) DC %.sup.(c) RY %.sup.(b) (12) --OAc 27
79.5 0
[0107] Although the alkene reacts, the desired product is not
obtained.
EXAMPLE 5 (COMPARATIVE)
[0108] In the Case of Styrene
[0109] The above operating conditions were repeated, using styrene
as the vinyl substrate. The results are collated in the table
below.
5 Test DC %.sup.(a) DC %.sup.(a) Comments BOA 1 65 10 By .sup.19F
NMR and GC/MS the formation of the "dimer" is detected (2
diastereoisomers)
[0110] Oligomerization or polymerization products are mainly
formed.
EXAMPLE 6
[0111] Comparison Between Vinyl Ethers and Vinyl Esters
[0112] The above operating conditions were carried out on various
substrates using triflyl chloride. The substrates used have
different values of Z.
6 Test Z DC %.sup.(a) RY %.sup.(a) BJ 542B OC.sub.12H.sub.25 68
23.5 BOA 142 SPh 91 22.5 BOA 137 OAc 82 52.5 RON 274
OCOC.sub.11H.sub.23 85 54
EXAMPLE 7
[0113] Unfavorable Role of the Phenyl Radical
[0114] The above conditions were used on various substrates, with
the value of Z being varied. The results are collated in the table
below. The ketone corresponds to the desired product after
elimination of an acyl chloride.
7 Substrate DC %.sup.(a) RY %.sup.(a) Formation of ketone
CH.sub.2.dbd.CH--OAc 82 52.5 -- CH.sub.2.dbd.C(CH.sub.3)--OAc 78.5
0 50 CH.sub.2.dbd.C(Ph)--OAc 69 1.5 5
CH.sub.2.dbd.C(CH.sub.3)--OSiMe.sub.3 89 0 28
CH.sub.2.dbd.C(Ph)--OSiMe.sub.3 57.5 0 9
EXAMPLE 8
[0115] Experimental Section: 9
[0116] The acyl herein is such that Ac--O-- is a propionate
[0117] Synthesis Starting with 2-Chloro-4,4,4-trifluorobutyl
Propionate (1)
[0118] 15% sodium hydroxide (107 mmol) and
2-chloro-4,4,4-trifluorobutyl propionate (1) (10.03 g, 49.0 mmol)
are loaded into a perfectly stirred and standardized 100-ml reactor
equipped with a condenser and a thermometer. The reactor is placed
in an oil bath at 90.degree. C. with stirring at 320 rpm. The
temperature of the medium reaches 84.degree. C. After 24 minutes,
the system is cooled with a bath of cardice. The medium is
two-phase and the lower phase is colorless. GC allows the partial
state of progress of the reaction to be monitored. The reactor is
placed at 90.degree. C. for 30 minutes at 520 rpm. The temperature
of the medium reaches 84.degree. C. The system is cooled in a bath
of cardice. Monitoring by GC indicates the end of the reaction. The
medium is two-phase and yellow. The lower phase is separated out by
settling. 4.11 g (RY.sub.assayed=46%) are recovered. In the same
manner, a second batch is carried out (30 minutes with stirring at
520 rpm). 4.43 g (RY.sub.assayed=43%) are recovered. The organic
phases are distilled off under atmospheric pressure simply with a
column head (t.sub.passage=68-83.degree. C.). 4.83 g of a colorless
liquid are recovered (P.sub.mass=96%).
[0119] Synthesis from the Alcohol (2):
[0120] 2-Chloro-4,4,4-trifluorobutan-1-ol (2) 10
[0121] 2-Chloro-4,4,4-trifluorobutyl propionate (1) (9.58 g, 95.8
mmol), methanol (92 ml, 2.3 mol) and concentrated sulfuric acid
(0.53 g, 10 mmol) are loaded into a 250-ml three-necked flask
equipped with a condenser, a thermometer, a septum and a magnetic
stirrer. The reaction medium is heated to reflux (between 60 and
65.degree. C.). The mixture is left stirring for 2.5 hours.
Distillation is performed at atmospheric pressure to remove the
methanol and the methyl acetate. The residue is distilled at
reduced pressure (38 mmHg). The following are collected:
[0122] 1st between 38 and 58.degree. C.: 0.318 g at more than 99%
pure
[0123] 2nd between 60 and 66.degree. C.: 10.15 g at more than 99%
pure
[0124] 3rd between 57 and 35.degree. C.: 0.63 g at more than 95%
pure.
[0125] 11.1 g are thus finally collected. Assay by 19F NMR gives a
RY.sub.isolated (2)=69%.
[0126] b.p.=60-65.degree. C./38 mmHg
[0127] 4,4,4-Trifluoro-1,2-epoxybutane (3)
[0128] 15% sodium hydroxide (37 mmol) and
2-chloro-4,4,4-trifluorobutan-1-- ol (2) are loaded into a
perfectly stirred and standardized 100-ml reactor equipped with a
condenser and a thermometer. The mixture is stirred at 20.degree.
C. for 1 hour 40 minutes at 250 rpm. A two-phase medium is
obtained. GC of the mixture indicates a virtually complete DC. The
mixture is allowed to settle for 2 hours. The two phases are
separated. The organic phase is washed with 5 ml of H.sub.2O. 3.1 g
of crude product are recovered. .sup.19F NMR analysis gives an
RY.sub.assayed (3)=68%
[0129] b.p.=68-69.degree. C./627 mmHg
EXAMPLE 9
[0130] 11
[0131] 3,3,3-Trifluoropropanal (18)
[0132] 1-Chloro-3,3,3-trifluoropropyl acetate (19) (10.02 g, 52.7
mmol), water (51 ml) and 95% sulfuric acid (1.5 ml, 26.6 mmol) are
loaded into a 100-ml four-necked flask equipped with a magnetic
stirrer, a cardice trap (connected to an antireturn bubbler) and a
thermometer. The mixture is heated to 105.degree. C. When the
temperature of the medium reaches 87.5.degree. C., a reflux
appears. The temperature falls by a few degrees (83.degree. C.).
The mixture is heated for 2 hours. It is then cooled to ambient
temperature and the trap is kept. The acetone in the trap is
replaced with warm water. The trap is washed with water and the
washing liquors are combined with the reaction medium. Assay by
.sup.19F NMR gives an RY.sub.assayed (18) of 89%. The
3,3,3-trifluoropropanal (18) is stored in the acidic aqueous
medium.
[0133] 3,3,3-Trifluoropropionic Acid (20)
[0134] 1-Chloro-3,3,3-trifluoropropyl acetate (19) (1.0 g, 5.3
mmol), water (5 ml) and 95% sulfuric acid (0.15 ml, 2.6 mmol) are
loaded into a 50-ml three-necked flask equipped with a magnetic
stirrer, a cardice trap (connected to an antireturn bubbler), a
thermometer and a Teflon tube. The mixture is heated to 105.degree.
C. When the temperature of the medium reaches 92.degree. C., a
reflux appears. The temperature falls by a few degrees (87.degree.
C.). The mixture is heated for 2 hours. It is then allowed to cool
to ambient temperature, and the trap is kept. The acetone in the
trap is replaced with warm water. The trap is washed with a minimum
amount of water. Assay by .sup.19F NMR gives an RY.sub.assayed (20)
of 73% (3.88 mmol). The solution of Oxone.RTM. (2.25 g, 3.67 mmol)
in 10 ml of water is prepared. This solution is added by syringe
pump over 30 minutes at 40.degree. C. The mixture is left at
40.degree. C. for 2 hours 15 minutes. 2.07 mmol of acid are
obtained with an RY.sub.oxidation (20)=73%.
EXAMPLE 10
[0135] 12
[0136] relative to: 13
[0137] The presence of a CH.sub.3 unit is not an inconvenience for
the trifluoromethylation reaction. However, the product of
vicinal-chlorotrifluoromethylation is not isolated; as a result of
the fact that there is now a tertiary carbon instead of a secondary
carbon--as in CF.sub.3CH.sub.2CHClOAc--this reaction brings about a
predominant elimination of acetyl chloride: 14
[0138] As shown by the results below, the intermediate (78) was
detected by working at lower temperature and by analyzing the
reaction medium after reaction for 1 to 3 hours: 15
8 (1)/ t DC % (1) DC % (74) RY (78) RY (82) Test (74)
.theta..degree. C. (h) %.sup.(b) %.sup.(a) %.sup.(b) %.sup.(b)
BJ665 1/1 80 1 60 65 28.5 7.5 2 68 75.5 21 19 BJ666 1/1 90 1 69 78
20 23 2 72 90 5 39 3 76 >95 1 39.5
[0139] (a) GC assay with internal standard, (b) assay by .sup.19F
NMR with internal standard: (78): .delta.=7.84 ppm (/TFA) and (82):
.delta.=8.97 ppm (/TFA).
* * * * *