title: Bi(OTf)3-catalyzed addition of isocyanides to 2H-chromene acetals: an efficient pathway for accessing 2-carboxamide-2H-chromenes.
abstract: Bismuth triflate (Bi(OTf)3) is identified as an efficient catalyst for the direct addition of isocyanides to 2H-chromene acetals. The large scope of isocyanides and chromene acetals makes them suitable substrates in this catalytic system. By this synthetic strategy, a polyfunctional molecular scaffold, 2-carboxamide-2H-chromenes could be prepared efficiently in one step up to 95% yield. In addition, this efficient and practical protocol proceeded smoothly in the gram scale even when the catalytic loading was reduced to 2 mol%.
authors: Department of Chemistry, South University of Science and Technology of China, Shenzhen, Guangdong 518055, China. wang.j@sustc.edu.cn.
authors: Longyun
authors: L
authors: Lyu
authors: Ming Yu
authors: MY
authors: Jin
authors: Qijie
authors: Q
authors: He
authors: Han
authors: H
authors: Xie
authors: Zhaoxiang
authors: Z
authors: Bian
authors: Jun
authors: J
authors: Wang