A metal-free, green strategy for intramolecular aminoalkoxylation of unfunctionalized olefins via catalysis using recyclable NIS, with water as the sole byproduct

Abstract

A green and metal-free strategy for the synthesis of structurally diverse prolinol derivatives through intramolecular aminoalkoxylation of unfunctionalized olefins in up to 96% isolated yields has been reported. This protocol uses easily recyclable NIS as the catalyst and proceeds under mild reaction conditions, using environmentally friendly alcohols as reaction solvents and alkoxylating agents. Notably, water is generated as the sole byproduct, emphasizing the green nature of the process. Experimental evidence and DFT calculations support a mechanistic pathway, proceeding via aziridinium ion formation rather than through iodonium intermediates; subsequent aziridinium ion ring-opening by alcohol affords the desired products. The NIS catalyst is readily regenerated under an oxygen atmosphere, eliminating the need for transition metals or stoichiometric oxidants. This robust and scalable approach thus represents a valuable advancement in the synthesis of prolinol derivatives and highlights the potential of cyclic aziridinium ion intermediates in sustainable nitrogen-heterocycle construction.