NOUVEAUX COMPLEXES OXO DE METAUX DE TRANSITION COORDINES AVEC UN ACIDE DE LEWIS - PROCEDE DE PREPARATION DE CES COMPLEXES - UTILISATION DE CES COMPLEXES EN TANT QUE CATALYSEURS DANS LA REACTION DE METATHESE DES OLEFINES

摘要

Novel oxo transition metal complex coordinated by the oxygen atom to a Lewis acid has formula (I) (Z is a Lewis acid; M is W, Mo or Re; R is a hydrocarbon gp. linked to M by a C atom; X is halogen or OR (R is as above); a is at least 1; and b is an integer the sum (a+b+2) being equal to the max. valency of M). (I) is used as a catalyst for the metathesis reaction of olefins. Use of (I) enables the metathesis reaction speed to be controlled as well as the sec. reactions; the reaction can also be reproduced and easily effected.