Iridium-Catalyzed Enantioselective C–H Borylation of Diarylphosphinates

P-stereogenic
phosphorus compounds are a ubiquitous and critically
important class of chiral ligands in asymmetric catalysis. Methods
for catalytic asymmetric synthesis via a step- and atom-economic way
are still very limited. We herein disclose a protocol of phosphinate-directed
iridium-catalyzed enantioselective ortho-H borylation
to construct P-stereogenic phosphorus compounds. A number of functional
groups could be well tolerated to afford optically active diarylphosphinates
with good to excellent enantioselectivities (up to 92% ee). We also
demonstrate the synthetic utilities of the obtained borylated products,
including the synthesis of precursors for chiral phosphine ligands.