Tridentate Directing Groups Stabilize 6‑Membered Palladacycles in Catalytic Alkene Hydrofunctionalization
journal contributionposted on 2017-10-03, 00:00 authored by Miriam L. O’Duill, Rei Matsuura, Yanyan Wang, Joshua L. Turnbull, John A. Gurak, De-Wei Gao, Gang Lu, Peng Liu, Keary M. Engle
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-homoallylamines, under Pd(II) catalysis. In conjunction with previous findings, we demonstrate regiodivergent hydrofunctionalization of 3-butenoic 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.
anti-Markovnikov addition productsCatalytic Alkene Hydrofunctionalization Removable tridentatepincer ligandsregiodivergent hydrofunctionalization3- butenoic acid derivativesalkene-containing substrate classesallylic alcohols4- pentenoic acidshomoallyl aminesgroup choice6- membered alkyl palladacycle intermediates