Cascade Cyclization of -Cyanamide Alkenes for the Divergent Synthesis of Azido-, Nitro-, and Alkenyl-Containing Pyrroloquinazolinones.

Radical cascade cyclizations of -cyanamide alkenes have been developed for the divergent synthesis of pyrroloquinazolinones bearing azido, alkenyl, and nitro groups by controlling the reaction conditions. The reaction temperature and the loading of the base play important roles in the different reaction pathways. These reactions are characterized by wide functional group compatibility and mild conditions.

Oxidative cascade cyclization of -arylacrylamides with TMSN.

An azido-radical-triggered cyclization of -(-cyanobiaryl)acrylamides with TMSN a C(sp)-N/C(sp)-C(sp)/C(sp)-N bond formation cascade is described. This reaction features mild conditions and high bond-forming efficiency, making it an efficient method for the construction of azide-substituted pyridophenanthridines.

Visible-Light-Promoted Cascade Cyclization of 3-Ethynyl-[1,1'-biphenyl]-2-Carbonitriles with Unsaturated α-Bromocarbonyls.

A visible-light-promoted cascade cyclization of 3-ethynyl-[1,1'-biphenyl]-2-carbonitriles with unsaturated α-bromocarbonyls for the synthesis of tetrahydrobenzo[]cyclopenta[]acridines is described. Three C(sp)-C(sp) bonds, one C(sp)-N bond, and three cycles can be formed in a single reaction through the addition of a C-centered radical to the carbon-carbon triple bond and three radical cyclizations. This reaction features mild conditions, wide substrate scope, and high bond-forming efficiency.

Azido-difluoromethylthiolation of Alkenes with TMSN and PhSOSCFH.

An oxidative azido-difluoromethylthiolation of alkenes by employing TMSN as the azide source and PhSOSCFH as the difluoromethylthiolation reagent is reported. The present method is characterized by good functional group tolerance, broad substrate scope, and short reaction time, thereby providing an efficient access to synthetically useful β-difluoromethylthiolated azides. Mechanistic studies indicate a radical pathway involved in the reaction.

Copper-Catalyzed Cascade Multicomponent Reaction of Azides, Alkynes, and Selenium: Synthesis of Ditriazolyl Diselenides.

A copper-catalyzed cascade multicomponent reaction for synthesizing ditriazolyl diselenides from azides, terminal alkynes, and elemental selenium has been developed. The present reaction features utilizing readily available and stable reagents, high atom-economy, and mild reaction conditions. A possible mechanism is proposed.