A NOVEL REACTION MODE OF A ETA(2)-ACYL INSERTING INTO A C-C BOND - THE CHEMISTRY ASSOCIATED WITH VANADIUM(III) BONDED TO A MESO-OCTAETHYL BIS(PYRIDINE)-BIS(PYRROLE) MACROCYCLE

The doubly homologated meso-octaethylporphyrinogen 1, containing two p yridine and two pyrrole rings in cis arrangements, allowed the synthes is of highly reactive vanadium(III) organometallics, via the intermedi acy of 2, t(8)(m-MeC(5)H(2)N)(C5H3N)(C4H2N)(2)Li-2(THF)(2)], and 3, [E t(8)(m-MeC(5)H(2)N)(C5H3N)(C4H2N)(2)V-Cl]. This latter complex has bee n converted to the corresponding [V-Me] derivative [Et(8)(m-MeC(5)H(2) N)(C5H3N)(C4H2N)(2)V-Me], which undergoes a facile carbonylation to 5, (m-MeC(5)H(2)N)(C5H3N)(C4H2N)(2)V-OC(CEt(2))(Me)]. The intermediate e ta(2)-acyl derivative thus found displayed an unusual carbenoid reacti vity inserting into a C-C bond.