Copper(II)/4‐Dimethylaminopyridine‐Mediated Oxidative Cyclization in Low‐Melting Mixtures: Access to Cyclopropane‐Fused Aza‐Heterocycles

A simple and efficient one‐pot approach has been developed for the stereoselective synthesis of 3‐azabicyclo[n.1.0]alkane derivatives, employing a low–melting mixture (LMM) composed of choline chloride (ChCl) and N , N ‐dimethylurea (DMU). This green and sustainable protocol facilitates the intramolecular oxidative cyclization of N ‐allyl malonamates to afford a diverse array of cyclopropane‐fused aza‐heterocycles in excellent yields. Furthermore, the utility of this methodology is exemplified in the concise and efficient synthesis of the antidepressant drug candidate GSK1360707.