C-H BOND ACTIVATION OF ALKENECARBOXYLATES BY RUTHENIUM COMPLEXES HAVING TRIPHENYLPHOSPHINE LIGANDS

Reactions of alkenecarboxylates with RuH(C2H4)(PPh(3))(2)(PPh(2)C(6)H( 4)) (1) or RuH2(PPh(3))(4) (2) give -alkoxycarbonyl-eta(3)-allyl-C-1,C -3)ruthenium(II) complexes, RuH(eta(3)-CH(R)CHCHCOOR')(PPh(3))(2) (R = H, R' = Me (3a), Et (3b), n-Bu (3c), cyclohexyl (3d); R = Me, R' = Me (4); R = Et, R' = Me (5a), cyclohexyl (5b)) in benzene at room temper ature. Reactions of 3a with CO, iodine, methyl acrylate and ethyl meth acrylate as well as the thermolysis result in the reductive eliminatio n of methyl crotonate. In the presence of ethylene, complex 5b is slow ly converted into dienecarboxylate complexes with concomitant hydrogen ation of ethylene to ethane.