A tunable electrosynthesis of sulfonyland bromo-substituted indolo[2,1-α]isoquinoline derivatives has been disclosed. In this reaction, a variety of easily available 2-aryl-N-acryloyl indoles can readily react with sulfonyl and/or bromine radicals, which are generated from arylsulfonyl hydrazides and potassium bromide respectively, to furnish the valuable sulfonyl-and bromo-substituted benzindolo-fused polycyclic compounds in moderate to good yields. Control experiment indicated that the reaction proceeds via a radical cascade cyclization pathway. This protocol features broad substrate scope and good functional group tolerance under transition metal-free and oxidant-free conditions.

New radical-triggered multi-component cyclizations of β-alkynyl propenones have been developed, leading to 50 examples of sulfonated 1-indenones with generally good yields and high levels of stereoselectivity. The oxidant-free azosulfonylation of β-alkynyl propenones with aryldiazonium salts and DABSO was realized under the neutral-redox conditions where TBHP enabled the direct selenosulfonylation of β-alkynyl propenones by combining sulfinic acids and diphenyl diselenide. This protocol features a broad substrate scope, high functional group tolerance and mild reaction conditions.

Deuterium-labeled) CF 2 H-and CFH 2 -moieties are of high interest in drug discovery. The high demand for the incorporation of these fluoroalkyl moieties into molecular structures has witnessed significant synthetic progress, particularly in the (deutero)hydrodefluorination of CF 3 -containing compounds. However, the controllable replacement of fluorine atoms while maintaining high chemoselectivity remains challenging. Herein, we describe the development of a selective (deutero)hydrodefluorination reaction via electrolysis. The reaction exhibits a remarkable chemoselectivity control, which is enabled by the addition of different organoboron sources. The procedure is operationally simple and scalable, and provides access in one step to high-value building blocks for application in medicinal chemistry. Furthermore, density functional theory (DFT) calculations have been carried out to investigate the reaction mechanism and to rationalize the chemoselectivity observed.

A novel visible-light photocatalytic bicyclization of β-alkynyl propenones with α-bromocarbonyls for highly diastereoselective synthesis of richly decorated syn-fluoren-9-ones is described. The reaction proceeds via a radical-triggered 5-exo-dig cyclization/1,6-H-abstraction/6-endo-trig cyclization cascade and offers a new and practical method for the assembly of 6/5/6 carbocyclic skeletons via C(sp3)-H alkenylation.

Tunable halofluoroalkylation and hydrofluoroalkylation of 1,6‐enynes were first reported by switching between copper‐catalysis and photocatalysis, leading to the atom‐economic and highly stereoselective protocols toward functionalized 1‐indenones with moderate to good yields. Copper‐catalysis enabled the concomitant incorporation of two important fluoroalkyl and halo functionalities into 1‐indenone skeleton, in which fluoroalkyl bromides were transformed into (E)‐1‐indenones as a major stereoisomer while fluoroalkyl iodides oriented complete Z‐selectivity to access (Z)‐1‐indenones. Specifically, photocatalysis allowed hydrofluoroalkylation of 1,6‐enynes to access fluoroalkylated (Z)‐1‐indenones under mild conditions, in which THF behaved as a hydrogen source. These two approaches feature remarkable compatibility with a wide variety of 1,6‐enynes and fluoroalkyl halides and excellent atomic utilization.magnified image