Access to Cycloalkeno[c]-Fused Pyridines via Pd-Catalyzed C(sp2)-H Activation and Cyclization of N-Acetyl Hydrazones of Acylcycloalkenes with Vinyl Azides

A novel Pd(II)-catalyzed vinylic C-H activation and cyclization has been developed, reacting a series of small, medium, and large N-acetyl hydrazones of acylcycloalkenes with vinyl azides to access diverse cycloalkeno[c]-fused pyridine scaffolds. This protocol provides progress in C(sp²)-H bond activation of medium to large cycloalkenes, and the target products can be obtained in a specific regioselectivity with good functional group tolerance and a broad substrate scope.

Design of hybrid heterocyclic systems with a furoxanylpyridine core via tandem hetero-Diels–Alder/retro-Diels–Alder reactions of (1,2,4-triazin-3-yl)furoxans

Synthetic strategy for the synthesis of hybrid heterocyclic systems with the furoxanylpyridine core based on the tandem hetero-Diels–Alder/retro-Diels–Alder reactions of (1,2,4-triazin-3-yl)furoxans with enamine and norbornadiene has been developed.