Catalytic Enantioselective [4+1]-Annulation of Carboxylic Acids with Cyclopropenes

An efficient asymmetric synthesis
of 3-vinyl­phthalides
has
been accomplished through rhodium-catalyzed [4+1]-annulation of arylcarboxylic
acids with cyclopropenes involving C–H bond functionalization.
The method exhibited excellent compatibility for various functional
groups and offered diverse substituted 3-vinyl­phthalides in
excellent yield and enantio­selectivity. Synthetic application
and control experiments were also performed to demonstrate the utility
and understand the reaction pathway.