Metathesis catalysts and reactions using the catalysts

Abstract

The invention relates to a method of forming an olefin from a first olefin and a second olefin in a metathesis reaction, comprising step (i): (i) reacting the first olefin with the second olefin in the presence of a compound that catalyzes said metathesis reaction such that the molar ratio of said compound to the first or the second olefin is from 1:500 or less, and the conversion of the first or the second olefin to said olefin is at least 50%, characterized in that as compound that catalyzes said metathesis reaction a compound of formula (A) is used: wherein M is Mo or W; Ris aryl, heteroaryl, alkyl, or heteroalkyl; optionally substituted; Rand Rcan be the same or different and are hydrogen, alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl; optionally substituted; Ris alkyl, alkoxy, heteroalkyl, aryl, heteroaryl, silylalkyl, silyloxy, optionally substituted; and Ris a residue R—X—, wherein X═O and Ris aryl, optionally substituted; or X═S and Ris aryl, optionally substituted; or X═O and Ris (R, R, R)Si; wherein R, R, Rare alkyl or phenyl, optionally substituted; or X═O and Ris (R, R, R)C, wherein R, R, Rare independently selected from phenyl, alkyl; optionally substituted; and to the catalysts used in the method.