A crystalline chiral phosphide for the synthesis of the first P-stereogenic P(iii) fluoride: a stable ligand for the Rh-catalyzed asymmetric arylation of isatins

Abstract

Stable P-stereogenic P(III) fluorides of the type *PR¹R²F have long resisted isolation, despite their great potential as ligands in asymmetric catalysis. We report the synthesis of a crystalline, chiral lithium alkene-phosphide that undergoes rapid, enantiospecific fluorination with N-fluorobenzenesulfonimide with retention of configuration to yield the corresponding fluorophosphinamide–alkene hybrid ligand in >99% ee. The ligand is configurationally stable up to 100 °C and forms a Rh(I) complex that catalyzes the base- and water-free asymmetric arylation of isatins to biologically important 3-hydroxyoxindoles with up to 99.5% ee.