1,5‐Conjugate Addition: A Potentially Valuable Synthetic Tool

Different from well-known 1,4- and 1,6-conjugate addition reactions, umpolung 1,5-addition is considered electronically mismatched and is rarely explored. With palladium hydride catalysis, 1,5-addition was recently proved to be feasible. Diverse types of C-, O-, and N-based nucleophiles can be enantioselectively introduced to the γ-position of electron-deficient conjugated dienes. A series of privileged cyclic structures can also be conveniently prepared through 1,5-addition-involved cascade processes with high stereocontrol. This article provides a perspective on the concept development and advancement of 1,5-conjugate addition, which has gradually emerged as a new synthetic model.