An easy-to-use, regioselective, and robust bis(amidate) titanium hydroamination precatalyst: mechanistic and synthetic investigations toward the preparation of tetrahydroisoquinolines and benzoquinolizine alkaloids

Chemistry. 2007;13(7):2012-22. doi: 10.1002/chem.200600735.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids / chemical synthesis
  • Alkaloids / chemistry*
  • Amination
  • Catalysis
  • Chemistry, Organic / methods*
  • Molecular Structure
  • Organometallic Compounds
  • Quinolines / chemical synthesis*
  • Quinolines / chemistry
  • Tetrahydroisoquinolines / chemical synthesis
  • Tetrahydroisoquinolines / chemistry*
  • Titanium / chemistry*

Substances

  • Alkaloids
  • Organometallic Compounds
  • Quinolines
  • Tetrahydroisoquinolines
  • Titanium