Rapid Access of Alkynyl and Alkenyl Coumarins via a Dipyridinium Methylide and Propargylamine Cascade Reaction
作者:Xinwei He、Ruxue Li、Pui Ying Choy、Tianyi Liu、On Ying Yuen、Man Pan Leung、Yongjia Shang、Fuk Yee Kwong
DOI:10.1021/acs.orglett.0c02674
日期:2020.9.18
A DMAP-catalyzed cascade approach allowing facile assembly of alkynyl coumarins is reported. By virtue of reactive o-AQM (in situ generated from modular propargylamine) and a new synthetic equivalent of acyl carbene (from pyridinium ylide), the reaction proceeds smoothly to afford a variety of alkynyl coumarins in good-to-excellent yields. This transition-metal-free and oxidant-free process features
据报道,DMAP催化的级联方法可以轻松组装炔基香豆素。借助于反应性邻-AQM(由模块化炔丙基胺原位生成)和新的酰基卡宾合成等同物(来自吡啶鎓内立德),反应顺利进行,从而以优异的产率获得了各种炔基香豆素。该无过渡金属和无氧化剂的工艺具有中等官能团耐受性,尤其是-Br基。因此,该协议规避了香豆素三氟甲烷磺酸钠的现有Sonogashira偶联剂的固有缺点。还发现这种通用方法可用于制备β-烯基香豆素,类似于当前的Heck型偶联反应的结果。