P-Trimethylsilylethanesulfonyl chloride

Preparative Methods can be most conveniently synthesized from commercially available Vinyltrimethylsilane (1) (eq 1), Radical addition of sodium bisulfite to the vinyl group catalyzed by f-butyl perbenzoate yields the sulfonate salt (2) which can be directly converted to SESCl (3) with Phosphorus(V) Chloride. The chloride (3) can then be purified by distillation. The intermediate sulfonate salt (2) is commercially available. The chloride (3) can also be prepared in 62% yield from the salt (2) using Sulfuryl Chloride and Triphenylphosphine (eq 2). A less convenient procedure to synthesize SESCl (3) using 3-trimethylsilylethylmagnesium chloride (4) and sulfuryl chloride has also been developed (eq 3).  

SESCI in Synthesis. The SES group has been used successfully in the synthesis of glycosides (eq 5). Reaction of (6) with SES-sulfonamide and lodonium Di-sym-collidine Perchlorate provides the iodo sulfonamide (7) in 82% yield. Treatment of (7) with (benzyloxy)tributylstannane in the presence of Silver ) Trifluoromethanesulfonate provides the p-benzyl glycoside (8). Fluoride treatment of (8) removes both the silyl ether and the SES group, giving the amino alcohol (9). 

The A -SES group can be incorporated by treating an aldehyde with (V-sulfinyl-p-trimethylsilylethanesulfonamide (SESNSO) (13), which can be made by treating the sulfonamide (12) with Thionyl Chloride and a catalytic amount of N,N-dichloro-p-toluenesulfonamide (eq 7) (see also N-Sulfinyl-p-toluenesulfonamide). The )V-sulfonyl imine can be used in situ in a number of reactions. For example, the A(-sulfonyl imine from aldehyde (14) reacts with 2,3-dimethylbutadiene (eq 8) to give the Diels-Alder adduct (15). Treatment of (15) with fluoride ion affords the bicyclic lactam (16). Also, the IV-sulfonyl imine derived from isobutyraldehyde and (13) reacts with Vinylmagne-sium Bromide to provide the allylic SES-sulfonamide (17) in 65% yield (eq 9).  

In a total synthesis of the antitumor antibiotic (—)-bactobolin (18), the choice of protecting group on the nitrogen was crucial (eq 10). Unlike other protecting groups, the SES group is compatible with a wide variety of transformations and reagents, and is easily removed at the end of the synthesis. 

Related Reagents. Benzenesulfonyl Chloride 4-Bromo-benzenesulfonyl Chloride Mesitylenesulfonyl Chloride Methanesulfonyl Chloride p-Toluenesulfonyl Chloride Tri-fluoromethanesulfonic Anhydride. 

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Trimethylsilyl-1-butyne, 218 l-Trimethylsilyl-2-butyne, 329 Trimethylsilyl chlorochromate, 327 Trimethylsilyldiazomethane, 327 p-Trimethylsilylethanesulfonyl chloride, 328... 

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