Highly active metathesis catalysts generated in situ from inexpensive and air stable precursors

摘要

The invention provides a process for the in-situ generation of a metathesis active catalyst of the formula: comprising contacting an NHC carbene with a dimer of the formula [(arene)MX1X]2 and an alkyne of the formula RC=CR1 or RC=EC-CR1 wherein M is ruthenium or osmium; X and X1 are the same or different and are each independently an anionic ligand; NHC is any N-heterocyclic carbene ligand; and, R and R1 are each independently hydrogen or a substituted or unsubstituted substituent selected from the group consisting of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, aryl, C1-C20 carboxylate, C1-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, aryloxy, C2-C20 alkoxycarbonyl, C1-C20 alkylthio, C1-C20 alkylsulfonyl and C1-C20 alkylsulfinyl. Preferably, the NHC is an s-IMES or IMES carbene ligand; the arene is preferably p-cymene and the alkyne is preferably acetylene. The invention further provides a process for ROMP and RCM reactions using the metathesis active catalysts.