モノ（ホスフィン）パラジウム（0）錯体触媒による高活性Markovnikov型ヒドロメタル化反応：ヘテロ二核ヒドリドパラジウム中間体の合成と反応性

Abstract

Syntheses of the heterodinuclear hydride complexes and their applications to catalytic hydrometallation reactions are described. Series of heterodinuclear palladium and platinum hydride complexes, L'2HPdMLn and L'2HPtMLn [L'=1/2 dppe, PMe3, PEt3, P(CH2Ph)3, PMe2Ph, PMePh2, PPh3, PCy3; MLn=MoCp(CO)3, WCp(CO)3, Mn(CO)5] are prepared by (i) the metathetical reaction of a mononuclear (halogeno)(hydrido)metal complex with an ate complex, (ii) the β-hydride elimination from the heterodinuclear ethyl complex, and (iii) the oxidative addition of a mononuclear hydride complex to a zerovalent metal complex. The reactions of L'2HPtMLn with electron-deficient alkenes lead to the reductive elimination to give the corresponding alkene complex of Pt(0) and MHLn. However, the similar treatment of L'2HPdMLn with electron-deficient alkenes gives the corresponding mononuclear alkyl complex MRLn. Mono(phosphine)palladium(0) complexes, Pd(diallyl ether)L' (L'=PPh3, PCy3, PMe3, PEt3) are found to be efficient active catalysts for the hydrometallation of electron-deficient alkenes of unreactive Mo, W, and Mn hydrides, MoHCp(CO)3, WHCp(CO)3, and MnH(CO)5. Scope and reaction mechanisms of the hydrometallation are described. This reaction involves a heterodinuclear hydridopalladium complex, L'HPdMLn as an active intermediate. An application of this catalysis to hydrosilylation of electron-deficient alkenes is also described.