Construction of C−C Axial Chirality via Asymmetric Carbene Insertion into Arene C−H Bonds

Abstract

By using diazonaphthoquinones and anilines as key reagents and through a point-to-axis chiral transfer strategy, the atroposelective synthesis via asymmetric C(sp 2 )ÀH bond insertion reaction of arenes has been realized under rhodium catalysis, providing the resulting biaryl atropisomers in moderate to excellent yields with good enantiomeric ratios (up to 99:1). Further elaboration indicates this type of axially biaryl scaffold may have promising potentials in developing novel chiral ligands.

Efficient Synthesis of Diaryl Quaternary Centers by Rh(II)/Xantphos Catalyzed Relay C−H Functionalization and Allylic Alkylation

“…Various metal‐carbenoid intermediates have found wide applications in synthetic chemistry due to their unique reactivities [15–32] . In this regard, the aromatic C( sp 2 )−H functionalization of electron‐rich aromatics with metal carbenes generated from diazo compounds has attracted considerable attention, and transition metal catalysts based on Rh, [33–44] Au, [45–55] Cu, [56–58] and Fe, [59–63] etc, have been developed for these valuable transformations (Scheme 1a,i) [64–70] . However, so far most of the protocols are still confined to reactions between two reactants with limited synthetic efficiency (Scheme 1a).…”