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Catalytic Asymmetric Michael Reaction of Keto Esters Effects of the Linker Heteroatom in Linked BINOL Keisuke Majima Ryo Takita Akihiro Okada Takashi Ohshima and Masakatsu Shibasaki Contribution from the Graduate School of Pharmaceutical Sciences The University of Tokyo Hongo Bunkyo ku Tokyo 113 0033 Japan J Am Chem Soc 2003 125 15837 15845 Professor Masakatsu Shibasaki Reagent of the year 1996 http www sigmaaldrich com suite7 Brands Fluka Riedel Home Miscellaneous Reagent of the Year 1996 html Review Matsunaga S Ohshima T Shibasaki M Adv Synth Catal 2002 1 344 Catalytic asymmetric Michael reaction Preparation La OiPr 3 NR Linked BINOL Remove solvent La NR Linked BINOL Pale yellow powder LSB Lanthanidecontaining chiral heterometallic complex ALB Aluminumcontaining chiral heterobimetallic complex Conclusion 1 Asymmetric induction occurs at the beta position of Michael acceptor was achieved by using La NR linked BINOL R H or Me complex 2 A linker heteroatom in linked BINOL can tune the catalyst profile electronically and sterically In general NMe ligand 2 was suitable for the combination of both small enones and beta keto esters and the NH ligand 1 was suitable for bulkier substrate 3 To generate the desired active species effectively maintaining the ration of the La NMelinked BINOL complex and beta keto ester at 1 2 to 1 10 was very important


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