Base-Promoted Tandem SNAr/Boulton-Katritzky Rearrangement: Access to [1,2,4]Triazolo[1,5-a]pyridines

A base-promoted tandem S_NAr/Boulton-Katritzky rearrangement is developed. It offers a simple and straightforward method for the formation of functionalized [1,2,4]triazolo[1,5-a]pyridines from 1,2,4-oxadiazol-3-amines or 3-aminoisoxazoles with 2-fluoropyridines.

Copper(i)-catalyzed asymmetric intramolecular C-arylation with ureas as the additives: highly enantioselective formation of spirooxindoles

A cooperative catalytic strategy is developed for a copper-catalyzed asymmetric intramolecular C-arylation reaction with ureas as the co-catalysts. By forming hydrogen bonds with 1,3-dicarbonyl structures, ureas can activate the substrates, stabilize the carbanion intermediates and the products, and fix the syn-configurations of 1,3-dicarbonyl structures. They help enhance the reactivity, prevent side reactions and improve the enantioselectivities.