Synlett 2005(11): 1699-1702  
DOI: 10.1055/s-2005-871535
LETTER
© Georg Thieme Verlag Stuttgart · New York

Cinchona Alkaloid-Sulfinyl Chloride Combinations: Catalytic Enantio­selective Sulfinylation of Alcohols

Norio Shibata*, Mitsuharu Matsunaga, Takeo Fukuzumi, Shuichi Nakamura, Takeshi Toru*
Department of Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan
Fax: +81(52)7355442; e-Mail: nozshiba@nitech.ac.jp; e-Mail: toru@nitech.ac.jp;
Further Information

Publication History

Received 28 April 2005
Publication Date:
14 June 2005 (online)

Abstract

A novel catalytic approach to asymmetric sulfinylation reaction based on the cinchona alkaloid-sulfinyl chloride combination strategy is described.

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Typical Experimental Procedure.
A solution of 9-fluorenol (25 mg, 0.13 mmol) in toluene (1 mL) was slowly added to a solution of 1 (0.025 mL, 0.20 mmol) and QDN (6.4 mg, 0.013 mmol) in toluene (2.0 mL) at -40 °C under nitrogen atmosphere. To this solution was then added a solution of proton sponge (72 mg, 0.34 mmol) in toluene (1 mL). After stirring at -40 °C for 36 h, the reaction was quenched with 1 N NaOH solution (5 mL). The mixture was extracted with CH2Cl2 (3 × 5 mL). The combined organic layer was dried over anhyd Na2SO4. The solution was evaporated under reduced pressure to give crude sulfinate, which was purified by column chromatography (silica 25 g, EtOAc-hexane = 1:9) to give 3b (54 mg, 90%, 94% ee).

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The catalytic enantioselective sulfinylation of alcohols using arenesulfinyl chlorides instead of alkanesulfinyl chlorides was attempted; however, the enantioselectivities of the arenesulfinates obtained were very low.