Synthesis of functionalized azetidines through chemoselective zinc-catalyzed reduction of β-lactams with silanes

摘要

An efficient method for the one-step conversionudof b-lactams to their corresponding functionalizedudazetidines has been developed. This approachudtakes advantage of the selective reductionudof the 2-azetidinone nucleus with hydrosilanes inudthe presence of a zinc-based catalyst. The methodologyudis tolerant towards sensitive groups such asudallene, ester, and cyanohydrin moieties. In addition,udthe process allows the preparation of enantiopureudazetidines without erosion of the stereochemical integrity.udA catalytic cycle involving an azetidiniumudsalt intermediate has been proposed.