Anti‐Markovnikov Addition of Anilines to Aliphatic Terminal Alkynes Catalyzed by an 8‐Quinolinolato Rhodium Complex

Abstract

Anti‐Markovnikov addition of anilines to aliphatic terminal alkynes proceeded using an 8‐quinolinolato rhodium/phosphine catalyst system. The use of a strong organic base, 1,1,3,3,–tetramethylguanidine, in the catalyst system enabled the formation of the aldimine products. Substrates with various functional groups including polar groups such as a phenolic hydroxy group are applicable to the hydroamination.

Carbofunctionalization of Terminal Alkynes via Rhodium Catalysis Enabling Formations of Four Different Bonds

“…First, when the β-alkylation of A is slow or unavailable, rhodium vinylidene I , existing in equilibrium with A , may enter an oxygenative addition pathway to form the open-chain product II . Second, a reactive primary aliphatic amine (e.g., benzylamine) can compete with pyridine N -oxide for addition to rhodium vinylidene B . Hydrolysis of the resultant hydroamination product III gives aldehyde IV .…”