Electron-Rich, Bicyclic Biaryl-Like KITPHOS Monophosphines via [4+2] Cycloaddition between 1-Alkynylphosphine Oxides and Anthracene: Highly Efficient Ligands for Palladium-Catalysed C-N and C-C Bond Formation

Abstract:

Electron-rich, bicyclic biaryl-like KITPHOS monophosphines have been prepared via Diels–Alder cycloaddition between 1-alkynylphosphine oxides and anthracene in an operationally straightforward and highly modular synthetic protocol that will allow access to an architecturally and electronically diverse family of ligands. Palladium complexes of these ligands are highly efficient catalysts for the Buchwald–Hartwig amination and Suzuki–Miyaura coupling of a wide range of aryl chlorides, which for the vast majority of substrate combinations outperform their o-(dicyclohexylphosphino) biphenyl-based counterparts.