Asymmetric Thermal Transformation, a New Way to Enantiopure Biphenyl-Bridged Titanocene and Zirconocene Complexes: Efficient Catalysts for Asymmetric Imine …

…, R Stürmer, HH Brintzinger

Index: Ringwald, Markus; Stuermer, Rainer; Brintzinger, Hans H. Journal of the American Chemical Society, 1999 , vol. 121, # 7 p. 1524 - 1527

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Citation Number: 96

Abstract

Enantiopure biphenyl-bridged titanocene and zirconocene complexes were obtained, by an asymmetric thermal transformation of the binaphthol complexes formed from the metallocene racemates and subsequent transformation to the corresponding dichlorides, in practically quantitative yields. Increased rates of this transformation in the presence of O2 gas or TEMPO indicate a radical reaction mechanism. The biphenyl-bridged titanocene ...