title: Enantioselective synthesis of tetrahydroprotoberberines and bisbenzylisoquinoline alkaloids from a deprotonated α-aminonitrile.
abstract: Under controlled conditions, 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-1-carbonitrile can be quantitatively deprotonated in the α-position. Its alkylation directly furnishes 3,4-dihydroisoquinolines which can serve as starting materials for the preparation of various alkaloids. Here, the preparation of the benzylisoquinolines (+)-laudanidine, (+)-armepavine, and (+)-laudanosine as well as the tetrahydroprotoberberines (-)-corytenchine and (-)-tetrahydropseudoepiberberine using Noyori's asymmetric transfer hydrogenation are described. The dimeric alkaloids (+)-O-methylthalibrine and (+)-tetramethylmagnolamine were obtained from nonracemic precursors in Ullmann diaryl ether syntheses.
authors: Institute of Organic Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
authors: Nancy
authors: N
authors: Blank
authors: Till
authors: T
authors: Opatz
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D044182:Benzylisoquinolines / Q000138:chemical synthesis* / Q000737:chemistry; D001600:Berberine Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D044182:Benzylisoquinolines; D001600:Berberine Alkaloids; D009570:Nitriles; C014845:berbine