Brønsted Acid-Catalyzed Carbonyl–Olefin Metathesis: Synthesis of Phenanthrenes via Phosphomolybdic Acid as a Catalyst
Yi Chen, Di Liu, Rui Wang, Xu Li, Jingyao Tan, Mao Shu, Lingfeng Tian, Yuan Jin, Xiaoke Zhang, Zhihua Lin
Abstract
Compared with the impressive achievements of catalytic carbonyl-olefin metathesis (CCOM) mediated by Lewis acid catalysts, exploration of the CCOM through Brønsted acid-catalyzed approaches remains quite challenging. Herein, we disclose a synthetic protocol for the construction of a valuable polycycle scaffold through the CCOM with the inexpensive, nontoxic phosphomolybdic acid as a catalyst. The current annulations could realize carbonyl-olefin, carbonyl-alcohol, and acetal-alcohol in situ CCOM reactions and feature mild reaction conditions, simple manipulation, and scalability, making this strategy a promising alternative to the Lewis acid-catalyzed COM reaction.