Synthesis of Indazolones via Friedel–Crafts Cyclization of Blocked (Masked) <i>N</i>-Isocyanates
作者:Eslam B. Elkaeed、Jing An、André M. Beauchemin
DOI:10.1021/acs.joc.7b01607
日期:2017.9.15
are rare amphoteric reagents with high, but underdeveloped synthetic potential. Herein, we study the formation of indazolones by Friedel–Crafts cyclization of N-isocyanates using blocked (masked) N-isocyanate precursors: the effect of the masking group and the reaction scope have been delineated. Substrate synthesis has also been improved using a reported copper-catalyzed coupling of arylbismuth(V) reagents
氮取代的异氰酸酯(N-异氰酸酯)是罕见的两性试剂,具有很高的合成潜力,但开发潜力不大。在本文中,我们研究了使用封端的(被掩蔽的)N-异氰酸酯前体通过Friedel-Crafts对N-异氰酸酯的环化形成吲哚酮的作用:已经描述了掩蔽基团的作用和反应范围。使用已报道的与半不稳定的OPh封端基团兼容的芳基铋(V)试剂的铜催化偶联也可以改善底物的合成。