An Easy-To-Use, Regioselective, and Robust Bis(amidate) Titanium Hydroamination Precatalyst: Mechanistic and Synthetic Investigations toward the Preparation of Tetrahydroisoquinolines and Benzoquinolizine Alkaloids
作者:Zhe Zhang、David C. Leitch、Man Lu、Brian O. Patrick、Laurel L. Schafer
DOI:10.1002/chem.200600735
日期:2007.2.23
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
A Smiles-type radical rearrangement induced by visible-light-mediated decarboxylation of ω-aryl-N-(acyloxy)phthalimides was developed, giving rise to pharmacologically important substance classes: phenylethylamine derivatives, dihydroisoquinolinones, and benzoazepinones were synthesized on the basis of readily available benzoic acids or benzaldehydes and β- or γ-amino acids. This methodology facilitates
Ligand effects on dirhodium(II) carbene reactivities. Highly effective switching between competitive carbenoid transformations
作者:Albert Padwa、David J. Austin、Alan T. Price、Mark A. Semones、Michael P. Doyle、Marina N. Protopopova、William R. Winchester、Andrea Tran
DOI:10.1021/ja00072a021
日期:1993.9
Carboxylate and carboxamide ligands of dirhodium(II) catalysts controlchemoselectivity in competitive metal carbene transformations of diazo compounds. For competitive intramolecular cyclopropanation versus intramolecular aromatic substitution with 1-diazo-3-aryl-5-hexen-2-ones, use of Rh 2 (OAc) 4 results in the products from both transformations in nearly equal amounts, but dirhodium(II) perfluorobutyrate
2-cyclohexanediyl backbone can be obtained in two steps from commercially available starting materials. In situ combination of this ligand with Ti(NMe 2 ) 4 or Zr(NMe 2 ) 4 results in the formation of bis(phenolato) complexes that catalyze hydroaminations ofalkynes and alkenes.