Synthesis and characterization of chiral enantiopure PC(sp3)P pincer ligands and their complexes

This paper reports an efficient synthetic approach to preparing optically active PC(sp3)P pincer ligands and their complexes. The reported synthetic scheme relies on a simple and straightforward carbo-Diels–Alder reaction cycloaddition of a readily available phosphine precursor, 1,8-bis-(diphenylphosphino)anthracene (2) with enantiomerically pure bis-(methyl-(S)-lactyl) fumarate (3) leading to the formation of chromatographically resolvable diastereomers 4 and 4′ that can be converted into a pair of enantiomerically pure antipodes 1 and 1′. We demonstrated that no racemization occurs upon complexation and metalation of the bifunctional PC(sp3)P pincer ligands. © 2021 Elsevier B.V.