title: An enantioselective strategy for the total synthesis of (S)-tylophorine via catalytic asymmetric allylation and a one-pot DMAP-promoted isocyanate formation/Lewis acid catalyzed cyclization sequence.
abstract: A new asymmetric total synthesis of a phenanthroindolizidine alkaloid (S)-tylophorine is reported, which features a catalytic asymmetric allylation of aldehydes and an unexpected one-pot DMAP promoted isocyanate formation and Lewis acid catalyzed intramolecular cyclization reaction. In addition, White's direct C-H oxidation catalyst system converting monosubstituted olefins to linear allylic acetates was also employed for late-stage transformation.
authors.affiliation: State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, People's Republic of China. wang98h@263.net wangqm@nankai.edu.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Su
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Meng
authors.initials: M
authors.lastname: Deng
authors.forename: Qingmin
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D003500:Cyclization; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry; D017953:Isocyanates / Q000138:chemical synthesis* / Q000737:chemistry; D058116:Lewis Acids / Q000737:chemistry*; D010616:Phenanthrenes / Q000138:chemical synthesis* / Q000737:chemistry; D010618:Phenanthrolines / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: C417980:4-(dimethylamine)pyridine; D000470:Alkaloids; D007212:Indolizines; D017953:Isocyanates; D058116:Lewis Acids; D010616:Phenanthrenes; D010618:Phenanthrolines; D011725:Pyridines; C521640:phenanthroindolizidine; C004218:tylophorine