Rhodium-catalyzed <i>ortho</i>-C–H alkylation of benzaldehydes with maleimides free of transient directing groups

A simple rhodium-catalyzed conjugate addition of C-H bonds to maleimides directed by a weakly coordinating aldehyde group was developed as a facile protocol to synthesize <i>ortho</i>-alkylated benzaldehydes in moderate to excellent yields (up to 90% yield). This protocol features operational simplicity and broad substrate scope, and requires no transient directing group.