Chiral organophosphorus compounds: from ligands to chiral auxiliaries

Organophosphorus compounds represent an important class of ligands in homogeneous catalysis due to their tunable electronic and steric properties. However, the stereochemical potential of phosphorus-centered chirality and its application as chiral auxiliaries remain relatively underexplored. In his thesis, Xiaobing Chen investigates the synthesis and applications of axially chiral phosphorus compounds, including BINOL-derived phosphoramidites and phosphonium salts, as platforms for stereochemical transfer and ligand development toward P-stereogenic compounds.

First, Chen introduces the fundamental concepts of molecular chirality and reviews synthetic strategies for accessing P-stereogenic compounds. He then describes a Ni-catalyzed stereoselective C-P cross-coupling strategy for the synthesis of P-chiral alkenylphosphonamidates via axial-to-central chirality transfer. Chen then presents nucleophilic additions to chiral alkenylphosphonium salts, enabling simultaneous formation of P- and C-stereogenic centers. He also reports a P(III)-directed Pd-catalyzed diastereoselective C(sp³)–H acetoxylation of phosphoramidites. 

Finally, Chen focusses on the development of carbon-centered ligands. He developed a modular strategy to access bench-stable phosphorus ylide precursors derived from bisphosphine scaffolds. These ligands exhibit strong σ-donor properties and tunable chiral environments and Chen successfully applied them in Pd-catalyzed asymmetric allylic substitution and explored them in Suzuki–Miyaura coupling and Ni-catalyzed transformations.