Molybdenum-based complexes with two aryloxides and a pentafluoroimido ligand: Catalysts for efficient z-selective synthesis of a macrocyclic trisubstituted alkene by ring-closing metathesis

Abstract

Olefin metathesis catalysts for controlling the formation of trisubstituted macrocyclic Z alkenes have been developed. The most effective complexes are Mo alkylidenes with a pentafluorophenylimido group and two large aryloxide ligands. The macrocyclic lactone precursor to anticancer agents epothilones B and D is obtained in 73 % yield and 91 % Z selectivity in less than 6 hours at room temperature. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.