A selective Ru-catalyzed semireduction of alkynes to Z olefins under transfer-hydrogenation conditions

Abstract

By using a readily available, air- and moisture-stable dihydrido-Ru complex, a variety of Z olefins are accessible under transfer-hydrogenation conditions with formic acid as the hydrogen source in excellent yields and Z/E selectivities. A discerning transformation: Z-Configured C=C bonds are stereoselectively formed from alkynes in the presence of a Ru catalyst with formic acid as the sole H2 source at room temperature (see scheme). A variety of functional groups are compatible with this novel procedure. Operational simplicity and the lack of overreduction products are characteristics for this unprecedented process. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.