53821-11-7Relevant articles and documents
Catalytic substitution/cyclization sequences of: O -substituted Isocyanates: Synthesis of 1-alkoxybenzimidazolones and 1-alkoxy-3,4-dihydroquinazolin-2(1 H)-ones
Wang, Qiang,An, Jing,Alper, Howard,Xiao, Wen-Jing,Beauchemin, André M.
, p. 13055 - 13058 (2017/12/15)
O-Substituted isocyanates (O-isocyanates) have rarely been used in organic synthesis, given their tendency to undergo side reactions (e.g., trimerization). Herein, we show that masked (blocked) O-isocyanate precursors allow one-pot or cascade reaction sequences featuring base-catalyzed substitution with 2-iodoanilines and 2-iodobenzylamines followed by copper-catalyzed cyclization, to form benzimidazolones and 3,4-dihydroquinazolin-2(1H)-ones. This work shows that O-isocyanates can serve as efficient building blocks for the synthesis of hydroxylamine-containing heterocycles.