Tridentate Directing Groups Stabilize 6-Membered Palladacycles In Catalytic Alkene Hydrofunctionalization

Removable tridentate directing groups inspired by pincer ligands have been designed to stabilize otherwise kinetically and thermodynamically disfavored 6-membered alkyl palladacycle intermediates. This family of directing groups enables regioselective remote hydrocarbofunctionalization of several synthetically useful alkene-containing substrate classes, including 4-pentenoic acids, allylic alcohols, homoallyl amines, and bis-homoallylamiries, under Pd(II) catalysis. In conjunction with previous findings, we demonstrate regiodivergent hydro-functionalization of 34Dutenoic acid derivatives to afford either Markovnikov or anti-Markovnikov addition products depending on directing group choice. Preliminary mechanistic and computational data are presented to support the proposed catalytic cycle.