title: Stereoselective synthesis of C-fused pyranoindoles, pyranobenzofurans and pyranobenzothiophene scaffolds using oxa-Pictet-Spengler type reaction of vinylogous carbonates.
abstract: C-fused pyranoheterocycles can be readily assembled using an intramolecular oxa-Pictet-Spengler type reaction of vinylogous carbonates in a highly stereoselective manner. Required indole and benzofuran rings tethered to vinylogous carbonates are prepared by a tandem Sonogashira coupling-nucleopalladation reaction. The entire process can also be carried out in a 'one-pot' manner starting from homopropargyl alcohol. The C-fused pyranoindoles could be converted to spirooxindoles as well as to ring expanded products under oxidative conditions.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai - 400076, India. sjgharpure@iitb.ac.in.
authors.forename: Santosh J
authors.initials: SJ
authors.lastname: Gharpure
authors.forename: V
authors.initials: V
authors.lastname: Prasath
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001572:Benzofurans; D007211:Indoles; D011714:Pyrans; D013876:Thiophenes; C088015:benzothiophene