Photocatalytic Nitrene Radical Anion Generation from Sulfonyl Azides for Intermolecular Aziridination of Unactivated Alkenes

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: May 3, 2025

Aziridines are important structures in the contemporary organic synthesis and used for several biological applications. Herein, we show that aziridines can be readily synthesized from alkenes by reductive activation of sulfonyl azides, mediated photoredox catalysis. Mechanistic studies indicate reaction proceeds through reactive nitrene radical anions instead more commonly encountered triplet nitrenes. A substrate scope is performed showed good functional group compatibility.

Language: Английский

Regioselectivity of non-Symmetrical Borylated Dienes via EnT Ca-talysis: Unveiling the Relationship between Structure and Reactivity

Published: Aug. 16, 2024

Energy transfer catalysis (EnT) has had a profound impact on contemporary organic synthesis enabling the construction of higher in energy, complex molecules, via efficient access to triplet excited state. Despite this, intermolecular reactivity, and unique possibility several reaction pathways central diradical rendered control over outcomes, an intractable challenge. Extended chromophores such as non-symmetrical dienes have potential undergo 2+2 cycloaddition, 4+2 cycloaddition or geometric isomerization, which, combination with other mechanistic considerations (site- regioselectivity), results chemical reactions that are challenging regulate. Leveraging spin density predictive tool, use core functionality can be adequately tuned potentially modulate would highly revealing intimate links between structure EnT induced reactivity. Herein, we utilize boron tool explore reactivity under catalysis, paying particular attention hybridization effects target Through site- regioselective was realized employed motif effecting efficiency. Reaction divergence enable achieved, while counterintuitive regiodivergence observed isomerization versus cycloaddition. The validated in-depth investigation determining origin competing processes

Language: Английский

Integration of N-Aryl Phenoxazine Photosensitizers and Nickel Catalysts in Polymer Supports Enhances Photocatalytic Organic Transformations

ACS Catalysis, Journal Year: 2024, Volume and Issue: unknown, P. 17609 - 17621

Published: Nov. 14, 2024

Enhancing the catalytic activity of photosensitizers is critical for photocatalysis, especially in dual systems. We present integration N-aryl phenoxazine and nickel-bipyridine catalysts into linear cross-linked polyacrylate matrices, creating robust polymer-supported photocatalysts. The flexible polymer confers good solubility organic solvents to ensure efficient interactions between sites substrates. proximity units nickel complexes copolymer P1-Ni boosts electron, energy, radical transfers, significantly enhancing photosensitizers. exhibits high catalyzing visible-light-driven sulfonylation, esterification, etherification reactions across a broad substrate scope at extraordinarily low catalyst loadings (0.1 0.2 mol %) with exceptionally turnover numbers approaching 1000. outperforms its homogeneous control by 27- 38-fold. Additionally, an insoluble (P2-Ni) was synthesized incorporating divinyl cross-linking agent. P2-Ni swells solvents, displays comparable that P1-Ni, readily recovered via centrifugal separation used six cycles minimal loss activity. This work demonstrates ability supports enhance activities photocatalytic transformations facilitating and/or transfers.

Language: Английский