2H-Indazoles are one class of the most important nitrogen-containing heterocyclic compounds. The 2H-indazole motif is widely present in bioactive natural products and drug molecules that exhibiting distinctive bioactivities. Therefore, much...

A radical di‐ and trichloromethylation/cyclization of unactivated alkenes was developed with commercially available dichloromethane and chloroform as di‐and trichloromethyl radical sources under metal‐free conditions. Variously substituted di‐ and trichloromethylated pyrrolo‐ and piperidino‐quinazolinones were obtained in 47–94% yields. Additionally, dibromomethylation/cyclization was also achieved under standard conditions when CH2Br2 was utilized. Moreover, the obtained dichloromethylated product can be transformed into 1′H‐spiro[cyclopropane‐1,3′‐pyrrolo[2,1‐b]quinazolin]‐9′(2′H)‐one after treating by KOH.

The synthesis of cyano-containing ring-fused quinazolin-4(3H)-one derivatives was developed under metal-free conditions. This reaction undergoes radical C(sp3)-H functionalization of alkyl nitriles, cascade radical addition/cyclization with N-alkylated quinazolinones to deliver the...

The annulation reactions of N-allylbenzamides with N-sulfonylaminopyridinium salts were developed under metal-free photoinduced mild conditions. Substituent-controlled sulfonaminoarylation and sulfonaminooxylation of benzamides were realized: N-allylbenzamides lead to benzosultams, while N-(2-phenylallyl)benzamides give sulfonamidylated oxazoline derivatives. Control experiments indicated that those reactions undergo a radical pathway with arylsulfonamidyl radicals as the intermediates. The aryl C−H bond functionalization in arylsulfonamidyl was involved for the first time to give benzosultams.

A metal-free polychloromethylation radical-initiated cyclization of unactivated alkenes was developed using CH2Cl2 and CHCl3 as the di- and trichloromethyl radical sources. Variously substituted N-allyl-indoles were successfully transformed into corresponding C2-(di-...