摘要：Thiagodos Santos,Cornelia S. Buettner, Dilara Berna Yildiz, Martina Mamone,Alessandro Ruffoni, and DanieleLeonori*

转自：康龙化成

Photochemical Conversion ofIndazoles into Benzimidazoles

Thiagodos Santos,Cornelia S. Buettner, Dilara Berna Yildiz, Martina Mamone,Alessandro Ruffoni, and DanieleLeonori*

Institute of Organic Chemistry,RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

—Angew.Chem. Int. Ed., 2025, 10.1002/anie.202423804

Recommended by Rui Jin _ MC5

KEYWORDS: photochemistry (反应类型),skeletal editing (反应类型), chemical permutation (反应类型), Csp2-N (成键类型), 1H-indazoles(原料), 2H-indazoles (原料), benzimidazoles (产物),HFIP (其他)

ABSTRACT: Daniele Leonori etal. introduce a photochemical strategy for the direct permutation of 1H- and2H-indazolesinto benzimidazoles. This transformation exploits the distinct photochemicalproperties of these heteroaromatics and proceeds under mild conditions. Throughsystematic experimental and computational studies, we have elucidated atwo-step mechanism involving excited-state tautomerization of 1H-indazoles,followed by photochemical rearrangement of the resulting 2H-isomers.This approach demonstrates broad substrate scope, high yields, andcompatibility with a variety of functional groups. This method can expand thestructural diversity of heterocycle-based libraries through the concept ofchemical permutation for heteroaromatic interconversion.

Background and this work

Optimization studies for the permutationof 1 into 1a

Investigation of the influence ofaromatic substitution patterns with common functional groups on photochemical reactivity

Substrate scope: photo-permutation of 1H-indazoles

Substrate scope: photo-permutation of N-alkyl 2H-indazoles

Prof.Daniele Leonoriet al. have demonstrateda photochemical method for the permutation of 1H-and 2H-indazolesinto benzimidazoles.This transformation leverages the distinct photochemical properties of theseheterocycles and proceeds under mild conditions, requiring only irradiationwithout the need for any additional reagent. The applicability of this approachwas demonstrated across a series of functionalized materials featuring avariety of functional groups, and stereogenic centers. Notably, the process provideshigh yields and excellent mass recovery, even with complex substrates,expanding the diversity and applicability of heterocycle-based libraries infragment-based drug design.

亚琛工业大学有机化学研究所Daniele Leonori课题组报道了一种将1H-或2H-吲哚重排成苯并咪唑的光化学方法。该反应除了光照无需任何额外的试剂，条件温和，底物适用范围广，扩展了药物分子设计的杂环化合物库，是制备杂环衍生物的一种强大而便捷的方法。

来源：新浪财经