The State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, China.
Org Lett. 2021 Mar 5;23(5):1880-1885. doi: 10.1021/acs.orglett.1c00286. Epub 2021 Feb 17.
In this report, a P(NMe)-mediated reductive intramolecular annulation reaction has been developed with benzoyl formates bearing a trisubstituted alkene unit. It provides a facile synthesis of highly functionalized 2,2-disubstituted -chromenes with a broad substrate scope and high efficiency. Experimental results suggest this annulation reaction proceeds via a cascade of alkene isomerization/vinyl -quinone methide formation/6π-electrocyclization. As a key intermediate, the vinyl-substituted -quinone methide is presumably generated by a Kukhtin-Ramirez adduct initiated O → C vinyl migration.
在本报告中，发展了一种含有三取代烯烃单元的苯甲酰基甲酸酯的 P(NMe)介导的还原分子内环化反应。该反应为具有广泛底物范围和高效率的高度官能化 2,2-二取代色烯提供了一种简便的合成方法。实验结果表明，该环化反应通过烯烃异构化/乙烯基-醌甲醚形成/6π-电环化的级联反应进行。作为关键中间体，乙烯基取代的-醌甲醚可能是由 Kukhtin-Ramirez 加合物引发的 O → C 乙烯基迁移生成的。
