C-H bond cleavage-enabled aerobic ring-opening reaction of in situ formed 2-aminobenzofuran-3(2H)-ones

DMAP-promoted oxidative functionalization of α-amino ketones via oxygen delivery from water/alcohols

This paper shows a novel oxidative functionalization of α-amino ketones to yield the corresponding α-ketoamides and α-acylimidates. The reaction proceeds via oxygen delivery from water/alcohols in conjunction with an electron acceptor and 4-dimethylaminopyridine (DMAP). Mechanistic study indicates that DMAP exhibits a dual function of nucleophilic catalysis and proton abstraction.

Oxidative Cross-Coupling of α-Amino Ketones with Alcohols Enabled by I2-Catalyzed C-H Hydroxylation

An I2-catalyzed oxidative cross-coupling of α-amino ketones with a wide range of alcohols is described. Using a combination of air and dimethyl sulfoxide (DMSO) as oxidants, the protocol allows an efficient synthesis of α-carbonyl N,O-acetals with high functional group tolerance and enables the late-stage introduction of α-amino ketones into biorelevant alcohols. Moreover, the present method can be used in the coupling of α-amino ketones with other kinds of nucleophiles, which demonstrates great generality for the functionalization of α-amino ketones. A preliminary mechanistic investigation suggests that C-H hydroxylation of α-amino ketones has been recognized as the key step followed by subsequent dehydration coupling.

Catalytic Asymmetric Umpolung Tandem Reactions of Hemiacetals via Dinuclear Zinc Cooperative Catalysis

The umpolung activity of hemiacetals serving as α-carbon nucleophiles has been reported via dinuclear zinc cooperative catalysis. This umpolung strategy has been applied to catalytic asymmetric tandem reactions of 1-tosylindoline-2,3-diols with β,γ-unsaturated-α-keto compounds, providing a broad series of structurally diverse tetrahydrofuran spirooxindoles and dihydrofurans, respectively. In addition, products could be transformed to quinazoline and quinoline derivatives.