title: An easy-to-use, regioselective, and robust bis(amidate) titanium hydroamination precatalyst: mechanistic and synthetic investigations toward the preparation of tetrahydroisoquinolines and benzoquinolizine alkaloids.
abstract: Amidate-supported titanium amido complexes are efficient and regioselective precatalysts for intermolecular hydroamination of terminal alkynes with primary amines. The synthesis and characterization of the first bis(amidate)-supported titanium-imido complex is reported. Its role as the active catalytic species is suggested in the course of product distribution studies using deuterated substrates. The bis(amidate)-supported precatalysts exhibit good functional-group tolerance, even performing hydroaminations in the presence of ester and amide groups. This functional-group tolerance was exploited in the synthesis of a variety of 1-substituted tetrahydroisoquinoline alkaloids and a one-pot hydroaminative procedure for the high yielding preparation of the benzo[a]quinolizine skeleton.
authors.affiliation: Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.forename: David C
authors.initials: DC
authors.lastname: Leitch
authors.forename: Man
authors.initials: M
authors.lastname: Lu
authors.forename: Brian O
authors.initials: BO
authors.lastname: Patrick
authors.forename: Laurel L
authors.initials: LL
authors.lastname: Schafer
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis / Q000737:chemistry*; D000586:Amination; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D015394:Molecular Structure; D009942:Organometallic Compounds; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry; D044005:Tetrahydroisoquinolines / Q000138:chemical synthesis / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D009942:Organometallic Compounds; D011804:Quinolines; D044005:Tetrahydroisoquinolines; D014025:Titanium