Ligand-Controlled C(sp3)–H Arylation: Synthesis of Chiral β-Ar-β-Ar'-α-Amino Acids from Alanine

The development of ligands that can promote selective insertion of a metal into primary or secondary C(sp 3 )–H bonds is a central challenge in the field of C–H functionalization. Here, we report a rare example of catalyst-controlled primary and secondary C(sp 3 )–H arylation using two different ligands. Successive application of these ligands enables the sequential hetero-diarylation of an alanine derivative with two different aryl iodides affording a wide range of β-Ar-β-Ar'-α-amino acids with excellent levels of diastereoselectivity (d.r. > 20:1). Both configurations of the β-chiral center can be accessed by choosing the order in which the aryl iodides are installed, thus demonstrating the potential to construct tertiary chiral centers from a simple methyl group. The realization of this reactivity by electronic and steric modulation of the ligands may provide fundamental guidance for the future design of more effective and selective catalysts for C(sp 3 )–H activation.