Pd-Catalyzed [3+2] cycloaddition of ketoimines with alkynes via directed sp3 C-H bond activation

The Pd(II)-catalyzed oxidative [3+2] cycloaddition of N-(2-pyridyl) ketoimines with internal alkynes has been developed. The transformation is tolerant of extensive substitution on halogen, alkene, alkyne, hydroxyl, aryl and acyl groups, and allows facile assembly of multisubstituted pyrroles.