748133-57-5Relevant academic research and scientific papers
An easy-to-use, regioselective, and robust bis(amidate) titanium hydroamination precatalyst: Mechanistic and synthetic investigations toward the preparation of tetrahydroisoquinolines and benzoquinolizine alkaloids
Zhang, Zhe,Leitch, David C.,Lu, Man,Patrick, Brian O.,Schafer, Laurel L.
, p. 2012 - 2022 (2008/02/04)
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 his(amidate)-supported titanium-imido complex is reported. Its role as the active catalytic species is suggested in the course of product distribution studies using deuteratcd substrates. The bis(amidate)-supported prccatalysts 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.
The synthesis of baclofen and GABOB via Rh(II) catalyzed intramolecular C-H insertion of α-diazoacetamides
Chen, Zhenliang,Chen, Zhiyong,Jiang, Yaozhong,Hu, Wenhao
, p. 1579 - 1586 (2007/10/03)
The synthesis of baclofen and GABOB is reported via hydrolysis of the corresponding N-tert-butyl γ-lactams, which were obtained from Rh(II) catalyzed intramolecular C-H insertion of α-diazoacetamides.
[Ind2TiMe2]: A general catalyst for the intermolecular hydroamination of alkynes
Heutling, Andreas,Pohlki, Frauke,Doye, Sven
, p. 3059 - 3071 (2007/10/03)
[Ind2TiMe2] (Ind=indenyl) is a highly active and general catalyst for the intermolecular hydroamination of alkynes. It catalyzes the reaction of primary aryl-, tert-alkyl-, sec-alkyl-, and nalkylamines with internal and terminal alkynes. In the case of unsymmetrically substituted 1-phenyl-2-alkylalkynes, the reactions occur with modest to excellent regioselectivities, whereby formation of the anti-Markovnikov regioisomers is favored. While the major product of hydroamination reactions of terminal arylalkynes is always the anti-Markovnikov isomer, alkylalkynes react with arylamines to preferably give the Markovnikov products. To achieve reasonable rates for the addition of sterically less hindered n-alkyland benzylamines to alkynes, these amines must be added slowly to the reaction mixtures. This behavior is explained by the fact that the catalytic cycle proposed on the basis of an initial kinetic investigation includes the possibility that the rate of the reaction increases with decreasing concentration of the employed amine. Furthermore, no dimerization of the catalytically active imido complex is observed in the hydroamination of 1-phenylpropyne with 4-methylaniline in the presence of [Ind2TiMe2] as catalyst. In general, a combination of [Ind2TiMe2]-catalyzed hydroamination of alkynes with subsequent reduction leads to the formation of secondary amines with good to excellent yields. Particularly impressive is that [Ind 2TiMe2] makes it possible for the first time to perform the reactions of n-alkyl- and benzylamines with 1-phenylpropyne in a highly regioselective fashion.
