Gold-catalyzed intermolecular tandem cyclization/[4 + 3] cycloaddition of 2-(1-alkynyl)-cyclopropyl pyridines with nitrones: an efficient strategy for the synthesis of [1,2]oxazepino[5,4-a] indolizines

A new method for the synthesis of seven-membered heterocycle-fused indolizine scaffolds from 2-(1-alkynyl-cyclopropyl)pyridines and nitrones under the catalysis of PPh 3 AuNTf 2 .