Carbanion methodology for alkylations and acylations in the synthesis of substituted oxazoles. The formation of Cornforth rearrangement products

A general and practical route to 4,5-disubstituted oxazoles using acid chlorides and isocyanides

An efficient and mild method for the synthesis of 4,5-di-substituted oxazolesvia[3 + 2] cycloaddition reaction of isocyanides and acid chlorides is reported.

General methodology for the preparation of 2,5-disubstituted-1,3-oxazoles

Deprotonation of 2-(phenylsulfonyl)-1,3-oxazole (1) readily provides a useful C-5 carbanion that is reactive with a variety of electrophiles. Aldehydes and ketones are useful substrates, and the formation of 5-iodo- and 5-tri-n-butylstannyl oxazoles affords access to cross-coupling reactions. Subsequent nucleophilic displacement of the 2-phenylsulfonyl group provides a general route for the synthesis of 2,5-disubstituted-1,3-oxazoles.