Functionality‐Directed Regio‐ and Enantio‐Selective Olefinic C−H Functionalization of Aryl Alkenes

Abstract

Aryl alkenes represents one of the most widely occurring structural motif in countless drugs and natural products, and direct C−H functionalization of aryl alkenes provides atom‐ step efficient access toward valuable analogues. Among them, group‐directed selective olefinic α‐ and β‐C−H functionalization, bearing a directing group on the aromatic ring, has attracted remarkable attentions, including alkynylation, alkenylation, amino‐carbonylation, cyanation, domino cyclization and so on. These transformations proceed by endo‐ and exo−C−H cyclometallation and provide aryl alkene derivatives in excellent site‐ stereo‐selectivity. Enantio‐selective α‐ and β‐ olefinic C−H functionalization were also covered to synthesis axially chiral styrenes.

Palladium-catalysed α and β C–H allylation of aryl alkenes

“…4 Significant progress has been made on chelation-assisted olefinic C–H functionalization of aryl alkenes. 5–13 The well-defined one is the β C–H functionalization of aryl alkenes by endo -metallocycles, including C–H alkynylation, alkenylation, cyanation and amino-carbonylation (Scheme 1a). 6–13 However, α C–H functionalization of aryl alkenes has attracted very limited attention, and the reported methods not only restricted to C–H alkenylation reactions but also employed only ( Z )-configurated aryl alkenes 14 or plain styrenes (Scheme 1b).…”