Synergistic silver/scandium catalysis for divergent synthesis of skeletally diverse chromene derivatives

Shuai Liu, Ke Chen, Xin-Chan Lan, Wen-Juan Hao,* Guigen Li, Shu-Jiang Tu,* Bo Jiang*

The combination of AgTFA and Sc(OTf)₃ enables the bimetallic synergistic catalysis of β-alkynyl ketones and o-hydroxybenzyl alcohols, allowing divergent synthesis of three classes of skeletally diverse chromene derivatives with generally good yields and high diastereoselectivity through dehydroxylated bi- and tricyclization cascades. The selectivity of these cycloadditions was controlled by adjusting the catalyst loading and reaction temperatures. The mechanisms for forming these compounds were proposed.

Chem. Commun. 2017, 53, 10692-10695