SYNTHESIS AND REACTIONS OF YNOL ESTER COMPLEXES OF MOLYBDENUM AND TUNGSTEN - CLEAVAGE OF THE RCCO-C(O)R' BOND AND OF THE RCC-OC(O)R' BOND OF YNOL ESTER LIGANDS

Reaction of the ketenyl complexes NEt4[M(eta-2-RCCO)(S2CNR"2)2(CO)] (3, M = Mo, R = Ph, R" = Et; 4, M = W, R = Ph, R" = Et (a), R = C6H4CMe3-4, R" = Et (b), R = Ph, R" = Me (c)) and K[W(eta-2-4-Me3C-C6H4CCO)(N2C6H7)2(CO)] (5) with acyl halides R'COCl (or R'COBr) affords the (ynol ester)metal complexes [M(S2CNR")2(CO)(eta-2-RCCOCOR')] (8: M = Mo, R = Ph, R'= Ph, R" = Et) (9: M = W, R = Ph, R' = Me (a), Ph (b), CHCH2 (c), trans-CHCHMe (d), trans-CHCHPh (e), R" = Et; R = C6H4CMe3-4, R' = Me (f), CH2Ph (g), CMe3 (h), R" = Et; R = Ph, R' = CMe3, R" = Me (i)) and [W(N2C6H7)2-(CO)(eta-2-4-Me3C-C6H4CCOCOR')] (10: R = C6H4CMe3-4, R' = CMe3 (a), CH2Ph (b), C6H4-OMe-4 (c)). Reaction of the ynol ester complexes [W(S2CNEt2)2(CO)(eta-2-4-Me3C-C6H4CCOCOCH2R)] (R = H (9f), Ph (9g)) with dimethylamine affords the ketenyl complex [H2NMe2][W(eta-2-4-Me3C-C6H4CCO)(S2CNEt2)2(CO)]. The ynol ester complexes [W(LL)2(CO)(eta-2-4-Me3C-C6H4CCOCOCH2Ph)] (LL = S2CNEt2 (9g), N2C6H7 (10b)) react with NaN(SiMe3)2 to give the ketenyl complexes Na[W(eta-2-4-Me3C-C6H4CCO)(LL)2(CO)]. Reaction of [W(S2CNEt2)2(eta-2-4-Me3C-C6H4CCOCOCMe3)(CO)] (9h) with HNMe2 gives [W(S2CNEt2)2-(eta-2-4-Me3C-C6H4CCNMe2)(CO)] (11). Reaction of 9h with PMe3 gives [W(S2CNEt2)2(eta-3-4-Me3C-C6H4CCSCSNEt2)(CO)][Me3CO2] (12). The reaction of 4b with PMe3 affords [W(eta-2-4-Me3C-C6H4CCO)(S2CNEt2)(CO)(PMe3)2] (13). The (ynol ether)metal complexes [M(S2CNEt2)2(CO)(eta-2-RCCOMe)] (6, M = Mo, R = Ph; 7, M = W, R = C6H4CMe3-4) were prepared by reaction of NEt4[M(eta-2-RCCO)(S2CNR"2)2(CO)] with CF3SO3CH3.