One-pot synthesis of group 8 transition metal carbene complexes useful as olefin metathesis catalysts

摘要

The invention provides a novel method for synthesizing transition metal carbene complexes useful as olefin metathesis catalysts. The method is a convenient one-pot synthesis in which transition metal carbenes are prepared in high yield from readily available starting materials via a dihydrogen complex containing two different anionic ligands, preferably a phosphine and a heteroatom-stabilized carbene. The invention additionally provides a method for synthesizing precursors to carbene ligands useful, inter alia, in the aforementioned one-pot synthesis. The precursors are in the form of trichloromethyl adducts of the formula L1-CCl3, where L1 is a heteroatom-stabilized carbene ligand, and are prepared by contacting an unsaturated, ionized analog of L-CCl3 with a non-nucleophilic base in the presence of chloroform.