{"title":"Cascade Alkynyl Prins Cyclization and Aza-Michael Reaction: En Route to Regioselective Pyrano- and Isochromenoquinoline Scaffolds","authors":"Subhamoy Biswas, Anil K. Saikia","doi":"10.1021/acs.joc.4c01916","DOIUrl":null,"url":null,"abstract":"A metal-free, Lewis acid approach for the regioselective synthesis of dihydropyranoquinoline scaffolds has been unveiled. The methodology employs a cascade alkynyl Prins–aza-Michael reaction sequence to deliver the products in good to excellent yields. The strategy features mild reaction conditions, broad substrate scope, and high functional group tolerance. The protocol has been further extended to include isochromenoquinoline derivatives. The utility of the reaction lies in the synthesis of highly fused polycyclic N,O-heterocycles via intramolecular Heck coupling. Additionally, a Rh(III)-catalyzed annulation results in the formation of highly fluorescent pentacyclic ammonium salts in excellent yields. Photophysical studies reveal that these pentacyclic ammonium salts exhibit strong emission in the green region (500–550 nm).","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Organic Chemistry","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1021/acs.joc.4c01916","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
引用次数: 0
Abstract
A metal-free, Lewis acid approach for the regioselective synthesis of dihydropyranoquinoline scaffolds has been unveiled. The methodology employs a cascade alkynyl Prins–aza-Michael reaction sequence to deliver the products in good to excellent yields. The strategy features mild reaction conditions, broad substrate scope, and high functional group tolerance. The protocol has been further extended to include isochromenoquinoline derivatives. The utility of the reaction lies in the synthesis of highly fused polycyclic N,O-heterocycles via intramolecular Heck coupling. Additionally, a Rh(III)-catalyzed annulation results in the formation of highly fluorescent pentacyclic ammonium salts in excellent yields. Photophysical studies reveal that these pentacyclic ammonium salts exhibit strong emission in the green region (500–550 nm).
期刊介绍:
The Journal of Organic Chemistry welcomes original contributions of fundamental research in all branches of the theory and practice of organic chemistry. In selecting manuscripts for publication, the editors place emphasis on the quality and novelty of the work, as well as the breadth of interest to the organic chemistry community.