Koilpitchai Sivamuthuraman, Venkitasamy Kesavan, Chemical Biology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai-600036, India.
Org Biomol Chem. 2019 Aug 14;17(30):7166-7171. doi: 10.1039/c9ob01069f. Epub 2019 Jul 22.
An organocatalytic diastereo- and enantioselective synthesis of 2,2'-disubstituted benzofuran-3-ones bearing adjacent quaternary and tertiary stereocenters has been achieved through Michael addition of 2-substituted benzofuran-3-ones to 2-enoyl pyridines. Both the enantiomeric forms of the major diastereomer were obtained using l-proline derived squaramide and quinine derived bis squaramide with excellent yield (up to 98%) and stereoselectivities (up to 97 : 3 dr and 98% ee). The control experiment revealed that the presence and position of nitrogen atoms in the 2-enoylpyridine have played a crucial role in the stereochemical outcome of the product.
通过 2-取代苯并呋喃-3-酮与 2-烯酰基吡啶的迈克尔加成，实现了具有相邻季碳和叔碳立体中心的 2,2'-二取代苯并呋喃-3-酮的手性催化非对映和对映选择性合成。使用脯氨酸衍生的双缩胍和奎宁衍生的双缩胍，可以以优异的收率（高达 98%）和立体选择性（高达 97:3 dr 和 98%ee）获得主要非对映异构体的两种对映异构体。控制实验表明，2-烯酰基吡啶中氮原子的存在和位置对产物的立体化学结果起着至关重要的作用。
