Insertion of strongly electron withdrawing cyanoolefins into the C-H bond in pentamethylcyclopentadienyl-rhodium(III) and -iridium(III) complexes containing P-O or P-O-O ' coordinations

Complexes Cp*MCl(MDMPP-P, O) (1a: M = Rh, 1b: M = Ir; eta (5)-C5Me5; MDMPP- P,O = PPh2(C6H3-2-O-6-MeO)) readily react with tcne or tcnq to form the 1:1 adducts [Cp*MCl(MDMPP-P, O)(ol)] (ol = tcne (c), tcnq (d)) (3ac: M = Rh, o l = tcne; 3bc: M = Ir, ol = tcne; 4ad: M = Rh, ol = tcnq; 4bd: M = Ir, ol = tcnq), derived from insertion of cyanoolefins into the C-H bond adjacent t o the metal-O bond. Complex Cp*Ir(TDMPPP,O,O') 2b (TDMPP-P,O,O' = P{C6H3-2, 6-(MeO)(2)}(C6H3-2-O-6-MeO)(2)) bearing a (P,O,O') coordination was treated with 1 equiv of tcne, tcnq, or Me-2-tcnq (e) to give the products in which one molecule of cyanoolefin was inserted, [Cp*Ir(TDMPP-P, O, O')(ol)] (5bc : ol = tcne; 6bd: ol = tcnq; 6be: ol = Me-2-tcnq). Reactions with 2 equiv o f cyanoolefin gave the products [Cp*Ir(TDMPP-P,O, O')(ol)(2)] (7bc: ol = tc ne; 8bd: ol = tcnq), in which insertion occurred at two C-H positions adjac ent to the Ir-O bonds. Structural data for 3ac, 3bc, 4ad, 5bc, and 7bc are described.