title: A one-pot cascade to protoberberine alkaloids via Stevens rearrangement of nitrile-stabilized ammonium ylides.
abstract: A facile one-pot synthesis of protoberberines from readily accessible 1,2,3,4-tetrahydroisoquinoline-1-carbonitriles and 1,2-bis(bromomethyl)arenes is described. The reaction cascade comprises four consecutive transformations, all of which can be effected under a single set of conditions. Ten protoberberines, including the alkaloids pseudopalmatine and pseudoepiberberine, were prepared in yields up to 86% according to this strategy. No chromatographic purification of the products is required, and the route is devoid of any protecting group manipulations.
authors.affiliation: Institute of Organic Chemistry, University of Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany.
authors.forename: Günther
authors.initials: G
authors.lastname: Lahm
authors.forename: Jan-Gernot
authors.initials: JG
authors.lastname: Deichmann
authors.forename: Anna Lisa
authors.initials: AL
authors.lastname: Rauen
authors.forename: Till
authors.initials: T
authors.lastname: Opatz
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry*; D064751:Ammonium Compounds / Q000737:chemistry*; D001600:Berberine Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D044005:Tetrahydroisoquinolines / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D064751:Ammonium Compounds; D001600:Berberine Alkaloids; D009570:Nitriles; D044005:Tetrahydroisoquinolines; C009090:protoberberine