Give Me an Ar, give Me an N! Arylation of the methyl group in a simple derivative of readily available alanine under palladium catalysis was followed by intramolecular amidation at the same position to give chiral α-amino-β-lactams with a wide range of aryl substituents (see scheme; Phth=phthaloyl). The α-amino-β-lactams were obtained in moderate to high yields with good functional-group tolerance and high diastereoselectivity.

Most chelation-assisted aliphatic C-H activation proceeds through a kinetically favored five-membered cyclometalated intermediate. Here, we report the first site-selective alkenylation of δ-C(sp(3))-H in the presence of more accessible γ-C(sp(3))-H bonds via a kinetically less favored six-membered palladacycle. A wide range of functional groups are tolerated, and the unique protocol can be applied to the synthesis of chiral piperidines. Moreover, mechanistic insights have been conducted to elucidate the origin of the unusual site-selectivity.

Transition metal-catalyzed direct functionalization of C-H bonds has recently emerged as a powerful strategy for the construction of carbon-carbon and carbon-heteroatom bonds. Among various metals employed, base metal copper has attracted significant attention owing to its relatively low cost, abundance, and versatile reactivity. This review aims to comprehensively summarize the recent advances in copper-mediated (both stoichiometric and catalytic) chelation-assisted functionalization of unactivated C-H bonds.Scheme 1 Copper-mediated cross-coupling and C-H functionalization.

A Pd(II)-catalyzed sulfonylation of unactivated C(sp(3))-H bonds with sodium arylsulfinates using an 8-aminoquinoline auxiliary is described. This reaction demonstrates excellent functional group tolerance with respect to both the caboxamide starting material and the sodium arylsulfinate coupling partner, affording a broad range of aryl alkyl sulfones. Moreover, the late-stage modification of complex molecules was achieved via this sulfonylation protocol.

A novel protocol for a Cu-catalyzed direct C((sp(2)))-H activation/intramolecular amination reaction of 6-anilinopurine nucleosides has been developed. This approach provides a new access to a variety of multiheterocyclic compounds from purine compounds via Cu-catalyzed intramolecular N-H bond tautomerism which are endowed with fluorescence.