Electrooxidative Dearomatization of Inactive Biphenyls to Cyclohexadienones.

An efficient electrooxidative dearomatization of inactive biphenyls has been developed under mild and easy-to-operate conditions. The protocol provides a powerful tool for the rapid synthesis of cyclohexadienones in moderate to high yields with wide substrate scope and good functional group compatibility even to oxidation-sensitive motifs. This method provides an environment-friendly and direct approach for the construction of C-O bonds with high regioselectivity.

Direct C(sp3)-H allylation of 2-alkylpyridines with Morita-Baylis-Hillman carbonates via a tandem nucleophilic substitution/aza-Cope rearrangement.

A base- and catalyst-free C(sp3)-H allylic alkylation of 2-alkylpyridines with Morita-Baylis-Hillman (MBH) carbonates is described. A plausible mechanism of the reaction might involve a tandem SN2' type nucleophilic substitution followed by an aza-Cope rearrangement. Various alkyl substituents on 2-alkylpyridines were tolerated in the reaction to give the allylation products in 26-91% yields. The developed method provides a straightforward and operational simple strategy for the allylic functionalization of 2-alkypyridine derivatives.

Electroselective and Controlled Reduction of Cyclic Imides to Hydroxylactams and Lactams.

An efficient and practical electrochemical method for selective reduction of cyclic imides has been developed using a simple undivided cell with carbon electrodes at room temperature. The reaction provides a useful strategy for the rapid synthesis of hydroxylactams and lactams in a controllable manner, which is tuned by electric current and reaction time, and exhibits broad substrate scope and high functional group tolerance even to reduction-sensitive moieties. Initial mechanistic studies suggest that the approach heavily relies on the utilization of amines (e.g., i-Pr2NH), which are able to generate α-aminoalkyl radicals. This protocol provides an efficient route for the cleavage of C-O bonds under mild conditions with high chemoselectivity.

Nickel-Catalyzed Electrochemical Phosphorylation of Aryl Bromides.

A nickel-catalyzed electrochemical cross-coupling reaction of aryl bromides with dialkyl phosphites, ethyl phenylphosphinate, and diphenylphosphine oxide has been developed. This reaction utilizes a simple undivided cell with inexpensive carbon electrodes to synthesize aryl phosphonates, aryl phosphinates, and arylphosphine oxides at room temperature. This protocol provides a mild and efficient route for the construction of C-P bond in moderate to high yields with broad substrate scope.