Free Radical Cascade Carbochloromethylations of Activated Alkenes

Abstract

Free radical carbochloromethylations of ortho-cyanoarylacrylamides and N-(arylsulfonyl)­acrylamides have been developed by employing simple alkyl chlorides as the chloromethyl source. The transformations are characterized by wide functional group compatibility and utilizing readily available reagents, thus providing efficient methods for constructing polychloromethyl-substituted quinoline-2,4-diones and α-aryl-β-polychloromethylated amides.

Cascade Cyclizations Triggered by Photochemically Generated Carbamoyl Radicals Derived from Alkyl Amines

“…In this context, N -arylacrylamides are versatile precursors possessing the ability to generate a variety of molecular architectures depending on the functionality flanking the acrylamide moiety. The ortho -cyano-substituted acrylamide motif is being actively studied by the synthetic community as it leads to the quinoline dione substructure, which is present in a plethora of important biologically active molecules. ,− Among methods that provide access to different derivatives of quinoline diones, a sulfonylative cyclization was reported by Yu and Li groups wherein the Yu group demonstrated a metal-free sulfonylative cyclization, and the Li group utilized Cu-catalyzed sulfonylation under conditions that were applicable to a larger selection of radicals for the annulation of 2-cyanoacrylamides. − Among other strategies for cyclization of acrylamide precursors, phosphorylation, , trifluoromethylation, difluoromethylation, , azidation, thiomethylation, and silylation are methods that have been well received by the scientific community. Our group has reported the visible light-mediated functionalization of CC and CN bonds ,, including the addition of carbamoyl radicals to quinone methides (Scheme b).…”

Visible-Light-Induced Cascade Arylazidation of Activated Alkenes with Trimethylsilyl Azide

“…In this field, the radical-mediated Smiles rearrangement has been demonstrated to be an efficient method for site-selective construction of C–C and C–heteroatom bonds . Since the pioneering work on trifluoromethylarylation of conjugated tosyl amides by the Nevado group, the radical-mediated difunctionalization of N -(arylsulfonyl)­acrylamides with various radical precursors, such as difluoroalkyl, trichloromethyl, phosphonyl, amino, aryl, and alkyl radical reagents, has been intensively developed in recent years, resulting in multifunctionalized amides with a quaternary stereocenter (Scheme a).…”