作者:Nadin Schläger、Andreas Kirschning
DOI:10.1039/c2ob26185e
日期:——
The Yamamoto aldol reaction is a vinylogous aldol reaction that relies on bulky aluminium-based Lewis acids. These activate both the aldehyde as well as become part of the enolate moiety. The report discloses the first detailed study on the substrate-controlled Yamamoto aldol reaction in which 2,3-syn and 2,3-anti disubstituted aldehydes serve as the stereodirecting elements. The “size” of the substituent in the β-position strongly determines the facial selectivity of enolate addition to the aldehyde. Large substituents favour formation of 1,3-syn diols while slim alkynyl groups preferentially lead to 1,3-anti products.
山本 aldol 反应是一种依赖于笨态铝基路易斯酸的传统 aldol 反应。这些路易斯酸不仅激活醛,还成为烯醇负离子部分的一部分。该报告首次详细研究了底物控制的山本 aldol 反应,其中 2,3-syn 和 2,3-anti 二取代醛作为立体导向元素。β-位取代基的“大小”强烈决定了烯醇添加至醛的面选择性。大的取代基有利于形成 1,3-syn 二醇,而纤细的炔基团则优先生成 1,3-anti 产品。