Palladium(0) Complexes with Unsymmetric Bidentate Nitrogen Ligands for the Stereoselective Hydrogenation of 1-Phenyl-1-propyne to (Z)-1-Phenyl-1-propene

作者：Martijn W. van Laren, Marcel A. Duin, C. A. de Klerk, Michele Naglia, Dominga Rogolino, Paolo Pelagatti, Alessia Bacchi, Corrado Pelizzi, Cornelis J. Elsevier · 发表于：Organometallics · 年份：2002 · DOI：10.1021/om0108346 · 被引用次数：62 · 研究领域：Asymmetric Hydrogenation and Catalysis、Organometallic Complex Synthesis and Catalysis、Catalytic C–H Functionalization Methods

A series of zerovalent palladium complexes Pd(NN)(alkene) of bi- or tridentate nitrogen ligands of the general formula 6-R‘ ‘-C 5 H 3 N-(C(R‘) NR)-2 (R‘ ‘ = H, Me, CH NR‘; R‘ = H, Me; R = alkyl, aryl, or amino group) and dimethylfumarate (dmfu) have been prepared and were subsequently employed as precatalysts in the homogeneous stereoselective semihydrogenation of 1-phenyl-1-propyne. An X-ray structure of Pd(C 5 H 4 N-(C(Me) N i -Pr)-2)(dmfu) was obtained. Whereas only relative small changes in substituents apply, the various complexes show very different stabilities under hydrogenation conditions. The complex Pd(C 5 H 4 N-(C(H) N(CH 2 ) 2 OH)-2)(dmfu) exhibits a good selectivity for the ( Z )-alkene but decomposes just before full conversion of the alkyne, whereas the complex Pd(C 5 H 4 N-(C(H) N i -Pr)-2)(dmfu) exhibits a good selectivity and stability under hydrogenation conditions and is a suitable catalyst for the stereoselective hydrogenation of 1-phenyl-1-propyne to ( Z )-1-phenyl-1-propene.