# Atroposelective Pd-Catalyzed C(sp 2)–P Coupling Enabling Modular Assembly of Axially Chiral QUINAPO Ligands

## TL;DR

A new method for efficiently creating chiral QUINAPO ligands using palladium catalysis is developed, enabling diverse and high-yield synthesis for asymmetric catalysis.

## Contribution

A general and modular Pd-catalyzed C(sp2)–P coupling method for axially chiral QUINAPO ligands is introduced.

## Key findings

- Axially chiral QUINAPOs are synthesized in 47–98% yields and up to 95% ee.
- The method allows rapid access to structurally varied QUINAPO frameworks.
- Representative ligands show high activity and enantioselectivity in asymmetric reactions.

## Abstract

QUINAP ligands have been widely employed in a broad range
of synthetically
valuable asymmetric transformations, and their oxidized analogues,
QUINAPOs, serve as effective Lewis base catalysts. Yet, a general
and modular synthesis of these scaffolds has remained elusive. Herein,
we present a Pd-catalyzed asymmetric C­(sp
2)–P coupling reaction of racemic heterobiaryl triflates with
secondary phosphine oxides that furnishes axially chiral QUINAPOs
in 47–98% yields and up to 95% ee across a broad substrate
scope. The platform is diversity-oriented, enabling rapid access to
structurally varied QUINAPO frameworks; subsequent deoxygenation delivers
the corresponding QUINAP ligands. Representative members exhibit high
activity and enantioselectivity in the asymmetric allylic alkylation
and alkynylation of chromones, highlighting how ligand substitution
modulates catalytic performance.