The mechanism of an aromatic C-H coupling reaction between heteroarenes and arylboronic acids using a Pd catalyst was theoretically and experimentally investigated. We identified the C-B transmetalation as the rate determining step. The (S)-catalyst-reactant complex was found to be stabilized by hyperconjugation between pi-orbitals on the tolyl group and the S-O sigma* antibonding orbital in the catalyst ligand. Our findings suggest routes for the design of new, improved Pd catalysts with higher stereoselectivity.
Aromatic C–H coupling with hindered arylboronic acids by Pd/Fe dual catalysts
An aerobicoxidativecoupling of arenes/alkenes with arylboronic acids (C–H/C–B coupling) usingcatalytic Pd(II)–sulfoxide–oxazoline (sox) ligand and iron–phthalocyanine (FePc) has been developed. This dual catalyst system enables the synthesis of sterically hindered heterobiaryls and styrene derivatives under air without stoichiometric co-oxidants. Additionally, this chemistry demonstrated an advance