1,2-Azaborolyls, Isoelectronic Analogues of the Ubiquitous Cyclopentadienyl Ligand: Synthesis of B-Heteroatom-Substituted 1,2-Azaborolyl Complexes and an Assessment of Their Electronic Features
1,2-Azaborolyls, Isoelectronic Analogues of the Ubiquitous Cyclopentadienyl Ligand: Synthesis of B-Heteroatom-Substituted 1,2-Azaborolyl Complexes and an Assessment of Their Electronic Features
Synthesis, Resolution, and Aldol Reactions of a Planar-Chiral Lewis Acid Complex
作者:Shih-Yuan Liu、Ivory D. Hills、Gregory C. Fu
DOI:10.1021/ja0552702
日期:2005.11.1
The synthesis and resolution of a new planar-chiral Lewis acid complex is described. The compound is applied to asymmetric Mukaiyama aldolreactions, leading to the formation of the desired product with good stereoselectivity. The sense of stereoselection is as predicted by the design, which exploits the ability of the Lewis acid to simultaneously serve as a sigma and a pi acceptor. Mechanistic observations
描述了一种新的平面手性路易斯酸配合物的合成和拆分。该化合物应用于不对称 Mukaiyama 羟醛反应,导致形成具有良好立体选择性的所需产物。立体选择的意义正如设计所预测的那样,它利用了路易斯酸同时充当 sigma 和 pi 受体的能力。机械观察与醛-路易斯酸复合物的定速形成一致,然后是快速亲核加成。