Photochemical Dearomative Cycloadditions of Quinolines and Alkenes: Scope and Mechanism Studies
Renyu Guo, Souvik Adak, Peter Bellotti, Xinfeng Gao, W. Walker Smith, Sam Ngan Le, Jiajia Ma, K. N. Houk, Frank Glorius, Shuming Chen, M. Kevin Brown
Abstract
Photochemical dearomative cycloaddition has emerged as a useful strategy to rapidly generate molecular complexity. Within this context, stereo- and regiocontrolled intermolecular para-cycloadditions are rare. Herein, a method to achieve photochemical cycloaddition of quinolines and alkenes is shown. Emphasis is placed on generating sterically congested products and reaction of highly substituted alkenes and allenes. In addition, the mechanistic details of the process are studied, which revealed a reversible radical addition and a selectivity-determining radical recombination. The regio- and stereochemical outcome of the reaction is also rationalized.