Catalytic Three‐Component Synthesis of Conjugated Dienes from Alkynes via Pd⁰, Pd^II, and Pd^IV Intermediates Containing 1,2‐Diimine

Abstract

Direct, efficient, selective, and catalytic all describe the synthesis of conjugated dienes from two molecules of alkyne, an organic halide, and tetramethyltin with 1 mol% of a (1,2-diimine)palladium complex in complex in DMF (see the catalytic cycle involving Pd0, PdII, and PdIV species on the right). Palladium–phosphane complexes do not catalyze this reaction. Furthermore, 1,4-dihalo-1,3-dienes were synthesized stoichiometrically from alkynes and molecular halogen.