Copper(II)-catalyzed preparation of alkylindium compounds and applications in cross-coupling reactions both in aqueous media

Unlocking the reactivity of the C-In bond: alkyl indium reagents as a source of radicals under photocatalytic conditions

Generation of organic radicals from organometallic compounds is a key step in metallaphotoredox cross-coupling reactions. The ability of organoindium compounds to serve as sources of alkyl radicals under light promoted oxidative conditions is described. Organoindium reagents were used in dual photocatalytic/nickel cross-coupling with aryl bromides. These reagents can be conveniently obtained from primary, secondary and tertiary alkyl bromides and chlorides using a novel indium(i) bromide/lithium bromide system. Both steps, the formation of organoindiums and their cross-coupling are insensitive towards air and moisture and tolerate a wide variety of functional groups.

Amine-Borane-Mediated, Nickel/Photoredox-Catalyzed Cross-Electrophile Coupling between Alkyl and Aryl Bromides

Nickel/photoredox catalysis has emerged as a powerful platform for exploring nontraditional and challenging cross-couplings. Herein, a metallaphotoredox catalytic protocol has been developed on the basis of a tertiary amine-ligated boryl radical-induced halogen atom transfer process under blue-light irradiation. A wide variety of aryl and heteroaryl bromides featuring different functional groups and pharmaceutical moieties were facilely coupled to rapidly install C(sp3)-enriched aromatic scaffolds. The compatibility of Lewis base-ligated borane with nickel catalysis was well exemplified to extend the chemical space for Ni-catalyzed cross-electrophile coupling.