The First Anti-Markovnikov Hydration of Terminal Alkynes: Formation of Aldehydes Catalyzed by a Ruthenium(II)/Phosphane Mixture.

With the right auxiliary phosphane ligands-for example, pentafluorophenyldiphenylphosphane or the sodium salt of 3,3',3″-phosphinidynetris(benzenesulfonic acid)-the ruthenium(II)-catalyzed hydration of terminal alkynes to aldehydes proceeds by the previously unknown anti-Markovnikov addition of water [Eq. (a)]. Complexes of the type [RuCl2 (PR2 R2' R″)x ] (R=alkyl, Ph) are discussed as catalytically active species. © 1998 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.