One-Step Synthesis of Isocoumarins and 3-Benzylidenephthalides via Ligandless Pd-Catalyzed Oxidative Coupling of Benzoic Acids and Vinylarenes
作者:Debkumar Nandi、Debalina Ghosh、Shih-Ji Chen、Bing-Chiuan Kuo、Nancy M. Wang、Hon Man Lee
DOI:10.1021/jo400174w
日期:2013.4.5
A straightforward synthetic method for the preparation of isocoumarins and 3-benzylidenephthalides via C–H olefination and oxidative coupling of readily available benzoicacids and vinylarenes was developed. The directing effect of the substituents on the benzoicacid allows for the synthesis of both types of lactone in pure form.
A ruthenium(II)-catalyzed annulation between two molecules of sulfoxonium ylides is achieved, generating a variety of substituted isocoumarins in reasonable yields. This strategy features dual C-H/C-C activation in one pot and has a wide substrate scope and good functional group tolerance.