title: Collective asymmetric synthesis of (-)-antofine, (-)-cryptopleurine, (-)-tylophorine, and (-)-tylocrebrine with tert-butanesulfinamide as a chiral auxiliary.
abstract: A collective asymmetric synthesis of phenanthroindolizidine and phenanthroquinolizidine alkaloids (-)-antofine, (-)-cryptopleurine, (-)-tylophorine, and (-)-tylocrebrine was achieved by means of a reaction sequence involving efficient generation of chiral homoallylic amine intermediates by asymmetric allylation of the corresponding tert-butanesulfinyl imine. From these intermediates, the pyrrolidine and piperidine rings were constructed by means of an intramolecular SN2 substitution reaction and a ring-closing metathesis reaction, respectively. The unusual C5-methoxy-substituted phenanthrene moiety of (-)-tylocrebrine was generated by means of an InCl3-catalyzed cycloisomerization reaction of an o-propargylbiaryl compound.
authors.affiliation: State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University , Tianjin 300071, People's Republic of China.
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Zheng
authors.forename: Yuxiu
authors.initials: Y
authors.lastname: Liu
authors.forename: Qingmin
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis / Q000737:chemistry*; D002073:Butanes / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry; D007536:Isomerism; D015394:Molecular Structure; D010616:Phenanthrenes / Q000138:chemical synthesis* / Q000737:chemistry*; D010618:Phenanthrolines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013449:Sulfonamides / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D002073:Butanes; D007211:Indoles; D007212:Indolizines; D010616:Phenanthrenes; D010618:Phenanthrolines; D013449:Sulfonamides; C473343:antofine; C511422:tert-butanesulfinamide; C007160:cryptopleurine; C031181:phenanthrene; C004218:tylophorine