ChiralC2-Boron-Bis(oxazolines) in Asymmetric Catalysis – A Theoretical Study of the Catalyzed Enantioselective Reduction of Ketones Promoted by Catecholborane
作者:Marco Bandini、Andrea Bottoni、Pier Giorgio Cozzi、Gian Pietro Miscione、Magda Monari、Rossana Pierciaccante、Achille Umani-Ronchi
DOI:10.1002/ejoc.200600133
日期:2006.10
computational results have provided a complete mechanistic picture, which explains the stereochemical outcome of the reaction. The B–BOXate complex binds both the reducing agent CATBH and the carbonyl compound, activating the former as a hydride donor and enhancing the electrophilicity of the latter. Moreover, the structure of two boron–BOX (BOXate) complexes has been confirmed by means of X-ray diffraction
通过 2,2'-亚甲基双(恶唑啉)(BOX)与儿茶酚硼烷(CATBH)反应制备的 C2-对称硼配合物可用作前手性酮的对映选择性还原的催化剂(5-10 mol%)。 ee 72–86 %),以令人满意的收率得到所需的醇。我们从理论上研究了 DFT 水平上氯苯乙酮的还原机理,计算结果提供了完整的机理图,解释了反应的立体化学结果。B-BOXate 复合物结合还原剂 CATBH 和羰基化合物,激活前者作为氢化物供体并增强后者的亲电性。此外,两种硼-BOX (BOXate) 配合物的结构已通过 X 射线衍射技术得到证实。 (© Wiley-VCH Verlag GmbH & Co.