Lewis Acid Mediated α-Thioalkylation of Ketones

Abstract

Lewis acid mediated α-alkylation of carbonyl compounds via silyl enol ethers is turning out to be a powerful synthetic method. For example, S_N1 reactive alkylating agents such as tertiary and aryl activated secondary alkyl halides, which are known to undergo undesired HX-elimination with lithium enolates or enamines, react regiospecifically and chemoselectively with the less basic silyl enol ethers¹. Related processes include Mukaiyamas version of the aldol condensation² as well as the addition of silyl enol ethers to tricarbo-