Rhodium-catalyzed tandem cyclization–cycloaddition reactions of enynebenzaldehydes: construction of polycyclic ring systems

o-(1,6-Enynyl)benzaldehydes underwent a novel mode of cycloaddition using Rh(I)-precatalyst, via[3 + 2] cycloaddition of presumed dipolar carbonyl ylide intermediate generated by Rh-catalyst and the utility of this mechanistically intriguing enyne cyclization can be found in a number of polycyclic natural product skeletons.