Remote Nucleophilic Substitution at a C(sp)-H Bond of α-Bromocarboxamides via 1,4-Hydrogen Atom Transfer To Access -Acyl-,-acetal Compounds.

Herein, we report a remote nucleophilic substitution reaction via 1,4-hydrogen atom transfer (1,4-HAT) to synthesize -acyl-,-acetal moieties. α-Bromocarboxamide undergoes rS at a C(sp)-H bond in the presence of an alcohol/phenol and a copper catalyst. Mechanistic studies using deuterated α-bromocarboxamide confirmed that the 1,4-HAT process is the rate-determining step.

Direct α-Tertiary Alkylations of Ketones in a Combined Copper-Organocatalyst System.

Herein, we report an efficient method for the tertiary alkylation of a ketone by using an α-bromocarbonyl compound as the tertiary alkyl source in a combined Cu-organocatalyst system. This dual catalyst system enables the addition of a tertiary alkyl radical to an enamine. Mechanistic studies revealed that the catalytically generated enamine is a key intermediate in the catalytic cycle.