1. A simple synthetic route to well-defined [Pd(NHC)Cl(1-tBu-indenyl)] pre-catalysts for cross-coupling reactions
- Author
-
Alberto Gobbo, Yaxu Liu, Kristof Van Hecke, Catherine S. J. Cazin, Thomas Scattolin, Marek Beliš, and Steven P. Nolan
- Subjects
Weak base route ,Chemistry ,Palladium indenyl complexes ,SUZUKI-MIYAURA REACTION ,Buchwald–Hartwig amination ,PRECATALYST ,Coupling reaction ,REACTIVITY ,Catalysis ,Inorganic Chemistry ,HETEROCYCLIC CARBENE COMPLEXES ,Simple (abstract algebra) ,Computational chemistry ,GENERAL-METHOD ,PD-PEPPSIC-N ,Buchwald-Hartwig amination ,LIGANDS ,Well-defined ,N-heterocyclic carbene ligands ,(NHC)PD(ALLYL)CL NHC ,Suzuki-Miyaura cross-coupling ,PD(I) - Abstract
The development of robust, more efficient, general, easily accessible Pd(II)-NHC pre-catalysts remains a key issue in cross-coupling applications. A selection of well-defined, air and moisture stable [Pd(NHC)Cl(1-Bu-t-indenyl)] (NHC=IPr, IPrCl, IMes, SIMes, IPr*) pre-catalysts have been synthesized in good to excellent yields by reacting [Pd(1-Bu-t-indenyl)(mu-Cl)](2) and various NHC.HCl precursors in the presence of the weak base K2CO3 in green acetone. The synthesized Pd(II)-NHC derivatives displayed excellent catalytic activity in classical Suzuki-Miyaura and Buchwald-Hartwig reactions, especially when IPrCl is employed as ancillary ligand. Additionally, in the challenging Suzuki-Miyaura reaction between esters and arylboronic acids, the [Pd(IPr*)Cl(1-Bu-t-indenyl)] complex exhibited the optimum catalytic activity under very mild reaction conditions.
- Published
- 2022