Synthesis of Unsymmetrical 3,4-Diaryl-3-pyrrolin-2-ones Utilizing Pyrrole Weinreb Amides
作者:Jessica G. Greger、Sarah J. P. Yoon-Miller、Nathan R. Bechtold、Scott A. Flewelling、Jacob P. MacDonald、Catherine R. Downey、Eric A. Cohen、Erin T. Pelkey
DOI:10.1021/jo2013516
日期:2011.10.21
A regiocontrolled synthesis of unsymmetrical 3,4-diaryl-3-pyrrolin-2-ones has been achieved in three steps from 1,2-diaryl-1-nitroethenes with pyrrole-2-carboxamides (pyrrole Weinreb amides) serving as the key linchpin intermediates. Two different methods for the preparation of the requisite nitroalkenes were investigated: (1) modified Henry reaction between arylnitromethanes and arylimines; and (2)
从 1,2-二芳基-1-硝基乙烯以吡咯-2-甲酰胺(吡咯 Weinreb 酰胺)作为关键的关键三步实现了不对称 3,4-二芳基-3-吡咯啉-2-酮的区域控制合成中间体。研究了两种不同的制备所需硝基烯烃的方法:(1)芳基硝基甲烷和芳基亚胺之间的改性亨利反应;(2) 2-芳基-1-溴-1-硝基乙烯与芳基硼酸的 Suzuki-Miyaura 交叉偶联反应。在芳基硝基甲烷的制备过程中遇到了一些困难,因此探索了一种被证明更有用的交叉偶联策略。1,2-二芳基-1-硝基乙烯与N-甲氧基-N之间的Barton-Zard吡咯环缩合反应-甲基-2-异氰基乙酰胺得到相应的吡咯 Weinreb 酰胺,然后分两步将其转化为所需的 3-吡咯啉-2-酮。总体而言,该方法允许构建 3,4-二芳基-3-吡咯啉-2-酮,并完全控制内酰胺羰基的取代基区域。通过制备八种不对称和对称的 3,4-diaryl-3-pyrrolin-2-ones,包括选择性