title: Lewis acid activation of carbodicarbene catalysts for Rh-catalyzed hydroarylation of dienes.
abstract: The activation of carbodicarbene (CDC)-Rh(I) pincer complexes by secondary binding of metal salts is reported for the catalytic site-selective hydro-heteroarylation of dienes (up to 98% yield and >98:2 γ:α). Reactions are promoted by 5 mol % of a readily available tridentate (CDC)-Rh complex in the presence of an inexpensive lithium salt. The reaction is compatible with a variety of terminal and internal dienes and tolerant of ester, alkyl halide, and boronate ester functional groups. X-ray data and mechanistic experiments provide support for the role of the metal salts on catalyst activation and shed light on the reaction mechanism. The increased efficiency (120 to 22 °C) made available by catalytic amounts of metal salts to catalysts containing C(0) donors is a significant aspect of the disclosed studies.
authors.affiliation: Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
authors.forename: Courtney C
authors.initials: CC
authors.lastname: Roberts
authors.affiliation: Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
authors.forename: Desirée M
authors.initials: DM
authors.lastname: Matías
authors.affiliation: Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Goldfogel
authors.affiliation: Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Meek