Hydride transfer reactivity of Mo(L)(H)(depe)2 (L = N, NBEt3)

Starting from Mo(N-2)(2)(depe)(2) (1), the nitrido complex Mo(N)(N-3)depe)(2) (2) was obtained by the reaction of 1 with Me3SiN3. Subsequent reaction of 2 with HCl in CH3OH afforded the cationic imido chloride 3, which could be converted into the nitrido chloride 4 with sodium bis(trimethylsilyl)amide. From 3 and 4 the hydrido complexes of the type Mo(H)(L)(depe)(2) [L = N (7), NBEt3 (8)] were obtained by the reaction with the hydride reagents LiBH4 and NaHBEt3. The hydridic character of the L,M-H bond of 8 was determined by DQCC measurements (bond ionicity i = 81%). Hydride reactivity studies were carried out on 7 and 8; however, only 8 underwent hydride transfer reactions. 8 reacted with 4,4'-dichlorobenzophenone and acetophenone to afford the corresponding alkoxide complexes Mo(NBEt3(OCHRR')(depe)(2) [R, R' = C6H4Cl (10); R = Me, R' = Ph (11)]. The high propensity of 8 to undergo carbonyl insertion was documented further by reactions with CO2 and carbonylmetal compounds. Conversion with CO2 led to formation of the formato complex Mo(NBEt3(OCHO)(depe)2 (9) and reactions with Fe(CO)(5) and Re-2(CO)(10) resulted in the formation of Mo[(mu-OCH)Fe(CO)(4)](NBEt3)(depe)(2) (12) and Mo[(mu-OCH)Re-2(CO)(9)](NBEt3)(depe)(2) (13). X-ray diffraction studies were carried out on 1-4, 6, 8-10 and 12-14. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)