Sequential Visible-Light Photoactivation and Palladium Catalysis Enabling Enantioselective [4+2] Cycloadditions

• DOI: 10.1021/jacs.7b08310
• Publication Date: 2017-09-27T22:29:10Z
• Authors: Miao-Miao Li; Yi Wei; Jie Liu; Hong-Wei Chen; Liang-Qiu Lu; Wen-Jing Xiao
• Keywords: Decarbonylation; Synergistic catalysis

Catalytic asymmetric cycloadditions of reactive ketene intermediates provide new opportunities for the production chiral heterocyclic molecules. Though known over 100 years, ketenes still remain underexplored in field transition-metal (TM)-catalyzed because (1) ketenes, as highly electron-deficient species, are possibly unstable to low-valence TMs (i.e., decarbonylation or aggregation) and (2) conventional thermal synthesis from acyl chlorides amines may be incompatible with TM catalysis chloride amine hydrochloride byproducts). Herein, we detail unprecedented [4+2] cycloaddition vinyl benzoxazinanones a variety via sequential visible-light photoactivation palladium catalysis. It is well demonstrated that traceless transient generation α-diazoketones through visible-light-induced Wolff rearrangement important success present cycloaddition. Furthermore, catalysts new, hybrid P, S ligand enable high reaction selectivity enantiocontrol.