2-Trifluoromethyl-5-(arylsulfonyl)methyl pyrroles and 2-trifluoromethyl-4-(arylsulfonyl)methyl pyrroles were selectively synthesized from trifluoromethyl-substituted 3-aza-1,5-enynes via a cyclization/sulfonyl group migration cascade catalyzed by AgOOCCF3 and CsOPiv, respectively. Alkylvinyl-substituted pyrroles were generated from seven-atom skeleton 3-aza-1,5-enynes via aryl sulfinic acid elimination in the presence of Cs2CO3. Two ion-pair intermediates were proposed and a key intermediate, aza-diene–yne, was successfully isolated in the mechanistic studies.

Methyleneaziridines reacted with diynes to generate fused anilines. This reaction involved a C2–C3 bond cleavage of methyleneaziridine. This work provides a new reaction pattern of methyleneaziridine.

Cyclization reactions of propargylic amides, due to their rapid assembly of structural complexity and good functional group compatibility, have gained considerable attention in recent years. These transformations have been successfully achieved with transition metals, halogen sources, Bronsted acids, and strong bases. Generally, the cyclizations proceed through a 5-exo-dig or 6-endo-dig fashion to furnish heterocycles.Figure optionsDownload full-size imageDownload as PowerPoint slide

The DABCO-catalyzed reaction of propargyl alcohols with dialkyl acetylene dicarboxylates and N-bromo-/N-iodosuccinimides under mild conditions has been developed. The reactions give 3-bromo-/3-iodo-2H-pyrans in up to 98% yield.

2-Trifluoromethyl-5-(arylsulfonyl)methyl pyrroles and 2-trifluoromethyl-4-(arylsulfonyl)methyl pyrroles were selectively synthesized from trifluoromethyl-substituted 3-aza-1,5-enynes via a cyclization/sulfonyl group migration cascade catalyzed by AgOOCCF3 and CsOPiv, respectively. Alkylvinyl-substituted pyrroles were generated from seven-atom skeleton 3-aza-1,5-enynes via aryl sulfinic acid elimination in the presence of Cs2CO3. Two ion-pair intermediates were proposed and a key intermediate, aza-diene–yne, was successfully isolated in the mechanistic studies.