A unique rhodium-catalyzed rearrangement process: isomerization of an alkyne to a 1,3-diene with concomitant migration of a formyl group. An expeditious route to dienals from readily available 4-alkynals

Abstract

In CH₂Cl₂, [Rh(BINAP)]BF₄ catalyzes the isomerization of 4-alkynals to dienals with excellent regio- and stereoselectivity; this new process compares favorably with previously reported methods for the synthesis of this class of compounds; a possible pathway for this unusual rearrangement is provided.