Recent Advances in Transformations Involving Electron‐Rich Alkenes: Functionalization, Cyclization, and Cross‐Metathesis Reactions

Unified metal-free intermolecular Heck-type sulfonylation, cyanation, amination, amidation of alkenes by thianthrenation

Direct and site-selective C-H functionalization of alkenes under environmentally benign conditions represents a useful and attractive yet challenging transformation to access value-added molecules. Herein, a unified protocol for a variety of intermolecular Heck-type functionalizations of Csp2-H bond of alkenes has been developed by thianthrenation. The reaction features metal-free and operationally simple conditions for exclusive cine-selective C-H functionalization of aliphatic and aryl alkenes to forge C-C, C-N, C-P, and C-S bonds at room temperature, providing a general protocol for intermolecular Heck-type reaction of alkenes with nucleophiles (Nu = sulfinates, cyanides, amines, amides). Alkenes undergo cine-sulfonylation, cyanation, amination to afford alkenyl sulfones, alkenyl nitriles and enamines.

Dual Photoredox/Copper Catalyzed Fluoroalkylative Alkene Difunctionalization

A method for performing radical difunctionalization of alkenes using fluorinated halides and a nucleophilic component (thiolate and iodide anions) is described. These nucleophilic fragments serve as redox active groups for performing subsequent transformations. The difunctionalization reaction involves photoredox generation of fluorinated radicals, their addition to the double bond followed by copper-promoted C-S or C-I bond formation. The primary products can be further coupled with silyl enol ethers, α-(trifluoromethyl)styrenes, and trimethylsilyl cyanide affording a variety of fluorinated compounds.

Exploring the regioselectivity of the cyanoalkylation of 3-aza-1,5-dienes: photoinduced synthesis of 3-cyanoalkyl-4-pyrrolin-2-ones

Regioselective cyanoalkylalkenylation of 3-aza-1,5-dienes with oxime esters induced by visible light.

Stereoselective Palladium-Catalyzed Arylation of Exo-Glycals with Aryl Iodides

A novel methodology for the arylation of exo-glycals has been developed. A range of exo-glycals underwent reactions with aryl iodides in the presence of a palladium catalyst. The transformation proceeded in a stereoselective manner to afford Z-isomers. The developed transformation demonstrated excellent functional group tolerance.