Photocatalyzed cascade Meerwein addition/cyclization of N-benzylacrylamides toward azaspirocycles.

A visible-light-induced cascade Meerwein addition/cyclization of alkenes involving C-F bond cleavage was developed. This method offers a rapid access to azaspirocyclic cyclohexadienones from N-benzylacrylamides via C-F bond cleavage applying H2O as an external oxygen source, allowing for the incorporation of various aromatic moieties originating from aryldiazonium salts.

Radical-mediated divergent cyclization of benzamides toward perfluorinated or cyanated isoquinolinediones.

A simple and efficient copper-controlled divergent cyclization of benzamides, which leads to perfluorinated or cyanated isoquinolinediones, is developed. In the presence of AIBN, methacryloyl benzamides with perfluoroalkyl iodides undergo cascade radical addition/cyclization to afford perfluoroinated isoquinolinediones as the major product under metal-free conditions, whereas the use of CuI (10 mol%) is able to redirect the cyclization to yield isoquinolinediones bearing an α-cyano quaternary carbon center. The cyclization features controllable divergent synthesis and a broad substrate scope as well as highly practical reaction conditions, thereby making this strategy a highly attractive means to fluorinate or cyanate isoquinolinediones.

Aerobic oxidative cyclization of benzamides via meta-selective C-H tert-alkylation: rapid entry to 7-alkylated isoquinolinediones.

A novel copper-catalyzed aerobic oxidative cyclization of benzamides via meta-selective C-H tert-alkylation using AIBN and analogues as radical precursors was described. This strategy provides an elusive and rapid means to 7-tert-alkylated isoquinolinediones, as well as the construction of tertiary alkyl-aryl C(sp(3))-C(sp(2)) bonds with positional selectivity.