The first copper-catalyzed intramolecular C(sp(3))-H and C(sp(2))-H oxidative amidation has been developed. Using a Cu(OAc)2 catalyst and an Ag2CO3 oxidant in dichloroethane solvent, C(sp(3))-H amidation proceeded at a terminal methyl group, as well as at the internal benzylic position of an alkyl chain. This reaction has a broad substrate scope, and various β-lactams were obtained in excellent yield, even on gram scale. Use of CuCl2 and Ag2CO3 under an O2 atmosphere in dimethyl sulfoxide, however, leads to 2-indolinone selectively by C(sp(2))-H amidation. Kinetic isotope effect (KIE) studies indicated that C-H bond activation is the rate-determining step. The 5-methoxyquinolyl directing group could be removed by oxidation.
A biocompatible photooxygenation catalyst that can selectively oxygenate and degrade the pathogenic aggregation of Alzheimer's disease (AD)-related amyloid-b peptide (Ab) under near-infrared light irradiation has been developed. The catalyst oxygenates Ab embedded under the skin of a living mouse and diminishes the intact Ab level in an AD-model mouse brain. The new catalyst is potentially applicable for the treatment of peripheral amyloid diseases and AD.
Chemo-and site-selective hydrosilylation of αor β-hydroxy amides using organocatalyst B(C 6 F 5 ) 3 and commercially available hydrosilanes is described. This transformation is operative under mild conditions and tolerates a wide range of functional groups. The reaction was applied for selective reduction of a specific amide group of the therapeutically important cyclic peptide cyclosporin A, demonstrating the potential usefulness of this catalytic method in late-stage structural transformations of drug lead molecules.
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