A One-Pot Photochemical Method for the Generation of Functionalized Aminocyclopentanes

Detailed herein is the development of a photo-chemical intermolecular formal [3+2] cycloaddition between cyclopropylimines and substituted alkenes to generate aminocyclopentane derivatives. The Schiff base of the cyclopropylimine was designed to enable a masked N-centered radical approach in which the requisite open-shell character was achieved upon excitation with visible light. The cycloaddition products were directly converted to N-functionalized aminocyclopentanes via solvolysis and N-acylation. The photochemical component of this reaction sequence was demonstrated to operate in continuous flow.

Automated summary

This article details the development of a photochemical reaction involving cyclopropylimines and substituted alkenes, which undergo a [3+2] cycloaddition to form aminocyclopentane derivatives. The use of a Schiff base enables a masked N-centered radical approach, which is activated upon excitation with visible light. The cycloaddition products can be directly converted to N-functionalized aminocyclopentanes through solvolysis and N-acylation. The photochemical component of this reaction has been demonstrated to be feasible in continuous flow.