Palladium-Catalyzed Cycloaddition of Alkynylimines, Double Isocyanides, and H<sub>2</sub>O/KOAc
Dianpeng Chen, Min Yang, Jianming Li, Peiying Cui, Lei Su, Yingying Shan, Jinmao You, Pornchai Rojsitthisak, Jin‐Biao Liu, Guanyinsheng Qiu
Abstract
In this work, a palladium-catalyzed cyclization of alkynylimines and double isocyanides is described. This facile procedure is efficient for synthesizing various 4-amidyl-2-aminopyrroles. Mechanism investigation indicates that a four-membered ring-fused pyrrole species is a key intermediate and the reaction involves [4 + 1] cycloaddition, protonation, nucleophilic addition, 1,4-addition of isocyanide, and rearomatization. Interestingly, the linear dipyrrole derivative is found to be an appropriate fluoride ion probe with a remarkable emission change, which could serve as a potential candidate for optoelectronic conjugated materials.