Generation and reaction of copper(I) hydride in the copper(I) chloride–tributyltin hydride–NMP system: synthesis of 3-norcephalosporin

Abstract

Synthesis of 3-norcephalosporin 1 was performed successfully by reaction of either 3-trifluoromethylsulfonyloxy-Δ³-cephem 2, allenecarboxylate 3 or 3,4-disubstitued but-2-enoates 4 with copper(I) chloride and tributyltin hydride in N-methylpyrrolidin-2-one (NMP). Generation and reactions of a copper(I) hydride species in the copper(I) chloride–tributyltin hydride–NMP or N,N-dimethylformamide (DMF) system are discussed.