Dimethylsulfoxonium methylide (DSM): A versatile reagent

Abstract

(A) Epoxidation: Recently, Hansen and co-workers have reported a DSM-promoted tandem aldol-epoxidation reaction which constructs three new stereocenters with complete diastereoselectivity.1 (Chemical Equation Presented) (B) Cyclopropanation: One-pot oxidative cyclopropanation reactions of activated alcohols can be brought about by DSM.2 (Chemical Equation Presented) (C) Aziridination: Dimethylsulfoxonium methylide affords difluoromethylaziridines upon reaction with difluoro enamines.4 (Chemical Equation Presented) (D) Extension of Esters: Using dimefhylsulfoxonium methylide, a variety of methyl esters can be converted into α-chloro ketones with extension of the carbon chain.5 (Chemical Equation Presented) (E) Diolefination of Cycloalkanones: Terminal/exocyclic 1,3-dienes are widely used in synthetic organic chemistry. Very recently, Butova and co-workers have synthesized exocyclic 1,3-dienes by a one-pot diolefination of cyclic ketones employing DSM and excess of a base at 130°C. Under these conditions the Corey reaction is suppressed and terminal 1,3-dienes are formed instead of epoxides. This reaction is termed as Yurchenko diolefination.6 (Chemical Equation Presented) (F) Ring Transformation: Coumarin derivatives with electron-withdrawing group at position 3 have been reported to undergo a novel ring transformation with DSM, which has been applied to the second-generation synthesis of (±)-linderol A.7 (Chemical Equation Presented) (G) Polymerization: Trialkyl and triaryl organoboranes undergo multiple, repetitive homologation upon reaction with DSM. The polyhomologation of 1-boraadamantane-THF with DSM generates a novel macrocyclic trialkylborane, which upon oxidation affords three-armed star polymethylene polymer incorporating a cis,cis-1,3,5-trisubstituted cyclohexane core.8 (Chemical Equation Presented) (H) Formation of Silyl Enol Ethers: Dimethylsulfoxonium methylide has been demonstrated to react with mono- and difluoroacetyltrialkylsilanes to give enol silyl ether products exclusively.9 (Chemical Equation Presented) (I) Ring Opening: N-Tosyl-protected 3-hydroxypyrrolidines are prepared by reaction of DSM with readily available epoxysulfonamides via regioselective ring-opening followed by 5-exo-tet cyclization in preference to oxetane formation.10 (Chemical Equation Presented). © Georg Thieme Verlag Stuttgart.