This report details the development of a masked N‐centered radical strategy that harvests the energy of light to drive the conversion of cyclopropylimines to 1‐aminonorbornanes. This process employs the N‐centered radical character of a photoexcited imine to facilitate the homolytic fragmentation of the cyclopropane ring and the subsequent radical cyclization sequence that forms two new C−C bonds en route to the norbornane core. Achieving bond‐forming reactivity as a function of the N‐centered radical character of an excited state Schiff base is unique, requiring only violet light in this instance. This methodology operates in continuous flow, enhancing the potential to translate beyond the academic sector. The operational simplicity of this photochemical process and the structural novelty of the (hetero)aryl‐fused 1‐aminonorbornane products are anticipated to provide a valuable addition to discovery efforts in pharmaceutical and agrochemical industries.

The use of lithium bis-catechol borate (LiB(cat)2) as a reductive quencher for the photoredox mediated intermolecular C–H functionalization of various heteroaromatics with bromopyrroloindolines is described. LiB(cat)2 offers a financial benefit over state-of-the-art quenchers currently in use while eliminating the side reactions that typically plague these couplings. The advantage of this methodology is highlighted by the synthesis of C3–C2′ (–) gliocladin C. Furthermore, additional examples of reactivity with various bromopyrroloindolines sets the stage for expedient routes towards other pharmaceutically active hexahydropyrroloindoline alkaloids and their analogues.

<div>Detailed herein is the development of a photochemical intermolecular formal [3+2] cycloaddition between cyclopropylimines and substituted alkenes to generate cyclopentylimines. The Schiff base auxiliary 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 violet light. The cycloaddition products were directly converted to N-functionalized aminocyclopentanes via N-acylation and solvolysis, thus offering a three-step, one-pot procedure for the production of diversely-substituted aminocyclopentanes. The photochemical component of this reaction sequence was demonstrated to operate in continuous flow and was amenable to gram-scale production.</div>

Detailed herein is the development of a photochemical 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.

<div>Detailed herein is the development of a photochemical intermolecular formal [3+2] cycloaddition between cyclopropylimines and substituted alkenes to generate cyclopentylimines. The Schiff base auxiliary 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 violet light. The cycloaddition products were directly converted to N-functionalized aminocyclopentanes via N-acylation and solvolysis, thus offering a three-step, one-pot procedure for the production of diversely-substituted aminocyclopentanes. The photochemical component of this reaction sequence was demonstrated to operate in continuous flow and was amenable to gram-scale production.</div>