Bi or Cd-induced coupling of sulfonyl chlorides with allylic halides. A simple synthesis of allylic sulfones

Article abstract of DOI:10.1055/s-1998-1877

The bismuth or cadmium-catalyzed coupling reaction between aryl and alkyl sulfonyl chlorides and allylic halides proceeds smoothly to provide excellent yields of allylic sulfones at ambient temperature.

Full text of DOI:10.1055/s-1998-1877

October 1998
SYNLETT
1083
Bi or Cd-Induced Coupling of Sulfonyl Chlorides with Allylic Halides. A Simple Synthesis of
Allylic Sulfones.
Mukulesh Baruah, Anima Boruah, Dipak Prajapati and Jagir S. Sandhu*
Regional Research Laboratory, Jorhat 785 006, Assam, India.
Received 10 June 1998
Abstract: The bismuth or cadmium-catalyzed coupling reaction
between aryl and alkyl sulfonyl chlorides and allylic halides proceeds
smoothly to provide excellent yields of allylic sulfones at ambient
temperature.
The sulfones has had considerable interest in organic synthesis as a
useful functionality and its utilisation in the synthesis of medicinally
1
important molecules . Many procedures can be used for the preparation
of sulfones while the most commonly employed methods involve the
oxidation of sulfides with peracids or with tetra-n-butylammonium
oxone, sulfonylation of aromatic hydrocarbons in the presence of a
Lewis acid and treatment of alkyl halides with alkali metal salts of arene
2,3
sulfinates . These methods are however, not always free from some
drawbacks such as unpleasant odor, long reaction times, competing side
reactions or insufficient conversion. Therefore, there is still merit in
developing a procedure for the preparation of sulfones using efficient
and inexpensive reagents. Moreover, in recent years considerable
4
resurgence of interest in the area of metal induced organic
transformations have figured prominantly. Herein we wish to disclose
the first example of bismuth-catalyzed coupling reactions of allylic
halides with sulfonyl chlorides under mild conditions to provide
excellent yields of allylic sulfones and there is no evidence of any side
reactions such as self-coupling or desulfonylation as reported by earlier
5
workers .
and needs 6-7 hrs with 40-50% conversion only (entry 13, 14 & 15).
Also attempts to couple 3-nitrobenzene sulfonyl chloride with allyl
In a typical case, to a solution of allyl bromide (1.2 mmol) in 10 ml of
absolute THF was added bismuth powder (1 mmol), and the resulting
bromide was not satisfactory (entry 11). When bismuth is replaced by
cadmium in the above reaction the coupling proceeds effectively and the
products were obtained in almost comparable yields. We have employed
bismuth and cadmium because these metals are readily available and
inexpensive. In most cases the reaction is over within (3-4) hrs with
bismuth powder, however the reaction takes little more time with
cadmium. Further increasing the reaction time gave no significant
improvement in yields but rather decomposition occurred. Similar
treatment of other sulfonyl chlorides gave the corresponding β,γ-
unsaturated sulfones in 70-90% yields and the typical results are
summerised in the table. All the compounds obtained were characterised
6
mixture was stirred at room temperature for 30 mins. Then p-toluene
sulfonyl chloride (200 mg, 1 mmol) in 5ml of THF was added dropwise
and progress of the reaction was monitored vide TLC. After 3 hours the
reaction was quenched with a few drops of water and extracted with
dichloromethane. The organic layer was separated, washed and dried
over anhydrous sodium sulfate. The solvent was removed on a rotary
evaporator and the residue was purified by column chromatography on
silica gel to get the corresponding allyl p-tolyl sulfone (entry 1) in 95%
yield exclusively. When crotyl bromide was used in place of allyl
bromide, the corresponding (E)-isomer (but-2-enyl p-tolyl sulfone) was
obtained in 92% yields, without the formation of any rearranged
products. This was confirmed by employing a secondary allylic halide
1
by infrared and H NMR spectroscopy and finally by comparison with
authentic samples.
7
In conclusion the present new procedure for the synthesis of unsaturated
sulfones provides much improvements over the existing methods and
will make a useful and important addition to the present methodologies.
The main advantages of this new method are mild reaction conditions,
tolerence to olefinic double bond and excellent yields of the products.
viz 3-chlorobut-1-ene in the above reaction (entry 10). The present
procedure was also applicable to an alkane sulfonyl chloride; a similar
reaction of methanesulfonyl chloride with allyl bromide led to
allylmethyl sulfone in 80% yield (Table). But the same reaction is not
equally effective when alkyl halides were used inspite of allyl halides

1084
LETTERS
SYNLETT
References and Notes :
(4) Trost, B. M. and Vranken, D. L. V., Chem. Rev., 1996, 395; For
the allylation of carbonyl compounds and imines using Cd or Bi
see: Sain, B., Prajapati, D. and Sandhu, J. S., Tetrahedron Lett.,
1992, 33, 4795; Bhuyan, P. J., Prajapati, D. and Sandhu, J. S.,
ibid., 1993, 34, 7975.
(1) Trost, B. M., Bull. Chem. Soc. Jpn., 1988, 61, 107.
(2) For
a review of sulfone chemistry see: Trost, B. M.,
Comprehensive Organic Synthesis, Pergamon Press, Oxford,
1991, Vol. 6, p-157; Magnus, P. D., Tetrahedron., 1977, 33, 2019.
(5) Frye, L. L., Sullivan, E. L., Cusack, K. P. and Funaro, J. M., J.
Org. Chem., 1992, 57, 697; Labadie, S. S., ibid., 1989, 54, 2496.
(3) For reports on Pd & Te - catalyzed coupling reaction of sulfonyl
chlorides see: Labadie, S. S., J. Org. Chem., 1989, 54, 2496 ;
Using tetra-n-butyl ammonium oxone see: Trost, B.M. and
Braslace, R., ibid., 1988, 53, 532; Suzuki, H., Nishioka, Y., S. I.
Padmanabhan, S. I. and Ogawa, T., Chem. Lett., 1988, 727 ; Using
Fluorides catalyst see: A. A. Kolomeitsev, A. A., Movchun, V. N.,
Kondratenko, N. V. and Yagupolski, Y. L., Synthesis, 1990, 1151 ;
Using Aliquat 336 see: Bram, G., Loupy, A., Roux-Schmitt, M.
C., Sansoulet, J., Strzalko, T. and Seyden-Penne, J., Synthesis,
1987, 56; Using Sodium formaldehyde sulfoxylate see: Harris, A.
R., Synthetic Commun., 1988, 18, 659 ; For a more recent
multistep report using (Phenylsulfonyl)-1,2-propadiene see:
Padwa, A. and Yeske, P. E., J. Org. Chem., 1991, 56, 6386.
(6) Bismuth and cadmium powder used were of commercial grade
and procured from Central Drug House (Pvt.) Ltd., New Delhi-
110 002; Sulfonyl chlorides used were obtained commercially and
distilled before use.
(7) The structure of the product with 3-chlorobut-1-ene as
1
unrearranged is confirmed by H NMR spectroscopy as δ 1.02 (s,
3H, CH ), 1.18 (d, J=6.9Hz, 3H, CHCH ), 3.20 (p, J=6.9Hz, 1H,
3
3
CHCH ), 5.15 (dd, J=8.1, ~1Hz, 1H, CH =C), 5.18 (dd, J=17.4,
3
2
~1Hz, 1H, CH =C), 5.72-5.88 (m, 1H, CH=CH ), 7.25 (d, 2H,
2
2
J=8.7Hz, aryl), 7.60 (d, 2H, J=8.7Hz, aryl).