HFIP-promoted halo-carbocyclizations of N- and O-tethered arene–alkene substrates to access all halo (X = Br, I, Cl)-functionalized tetrahydroquinoline and chroman cores. Issue 41 (11th October 2022)

• Record Type: Journal Article
• Authors: Shukla, Pushpendra Mani; Bhattacharya, Aditya; Pratap, Aniruddh; Pradhan, Akash; Sinha, Puspita; Soni, Tanishk; Maji, Biswajit
• Is Part Of: Organic & biomolecular chemistry. Volume 20:Issue 41(2022)
• Page Start: 8136
• Page End: 8144
• Publication Date: 2022-10-11
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d2ob01597h
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Herein, a HFIP-promoted mild and efficient method for the synthesis of all halo (X = Br, I, Cl)-functionalized tetrahydroquinoline and chroman building blocks is disclosed. Abstract : A new method for the stereoselective metal-, additive- and oxidant-free Friedel–Crafts-type halo-carbocyclization of N - and O -tethered arene–olefin substrates is reported, involving reaction with a suitable electrophilic halogenating reagent (NXS/DCDMH) in hexafluoroisopropanol. All halo (X = Br, I, Cl)-functionalized tetrahydroquinolines and chromans were obtained in excellent yields and with high levels of diastereocontrol (dr = >99 : 1), and these products were successfully transformed into synthetically useful compounds such as dihydroquinolines and partial or full azahelicene compounds.