| 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; R 1 is aryl, heteroaryl, alkyl, or heteroalkyl; optionally substituted; R 2 and R 3 can be the same or different and are hydrogen, alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl; optionally substituted; R 5 is alkyl, alkoxy, heteroalkyl, aryl, heteroaryl, silylalkyl, silyloxy, optionally substituted; and R 4 is a residue R 6 -X-, wherein X = O and R 6 is aryl, optionally substituted; or X = S and R 6 is aryl, optionally substituted; or X = O and R 6 is (R 7 , R 8 , R 9 )Si; wherein R 7 , R 8 , R 9 are alkyl or phenyl, optionally substituted; or X = O and R 6 is (R 10 , R 11 , R 12 )C, wherein R 10 , R 11 , R 12 are independently selected from phenyl, alkyl; optionally substituted; and to the catalysts used in the method. |