Titanium hydroamination catalysts bearing a 2-aminopyrrolinato spectator ligand: monitoring the individual reaction steps
作者:Katharina Weitershaus、Benjamin D. Ward、Raphael Kubiak、Carsten Müller、Hubert Wadepohl、Sven Doye、Lutz H. Gade
DOI:10.1039/b902038a
日期:——
ligand N(Xyl)N}(-) as the ancillary ligand, have been prepared and are shown to be pre-catalysts for the hydroamination of alkynes. The coordination of N(Xyl)N}(-) to titanium was achieved by reaction of [Cp*TiMe(3)] with the protioligand N(Xyl)NH giving [Cp*Ti(N(Xyl)N)(Me)(2)] (). Upon reaction of complex with an excess of tert-butylamine, the imido complex [Cp*Ti(N(Xyl)N)(N(t)Bu)(NH(2)(t)Bu)] () was
microwave technology, it is possible to achieve turnover frequencies TOF > 10 h−1. Furthermore, when Cp2TiMe2 is used as the catalyst, hydroamination products of terminal alkynes can be isolated in reasonable yields for the first time. The addition of amines to terminal alkynes gives access to both the Markovnikov and the anti-Markovnikov products. Observed regioselectivities are different for terminal
[Ind2TiMe2]: A General Catalyst for the Intermolecular Hydroamination of Alkynes
作者:Andreas Heutling、Frauke Pohlki、Sven Doye
DOI:10.1002/chem.200305771
日期:2004.6.21
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 [Ind(2)TiMe(2)] as catalyst. In general, a combination of [Ind(2)TiMe(2)]-catalyzed hydroamination of alkynes with subsequent reduction leads to the formation of secondary amines with good to excellent yields
Pyrimidopteridine-Catalyzed Hydroamination of Stilbenes with Primary Amines: A Dual Photoredox and Hydrogen Atom Transfer Catalyst
作者:Tobias Taeufer、Richy Hauptmann、Firas El-Hage、Thea S. Mayer、Haijun Jiao、Jabor Rabeah、Jola Pospech
DOI:10.1021/acscatal.0c05540
日期:2021.4.16
potent organic pyrimidopteridine photoredox catalyst (E*[PrPPT*/PrPPT·–] = +2.10 V vs SCE in MeCN), the photo-mediated hydroamination of stilbenes was enabled using unprotected, primary aliphatic, allylic, benzylic amines for the synthesis of various α-phenyl phenethylamine derivatives. Notably, the stereogenic center of α-chiral amines was fully preserved. Both starting materials serve as competent quenching
addition reactions of very weakly acidic nonactivated alkylarenes such as toluene and its derivatives were developed by using a strongly basic mixed catalyst system under mild reaction conditions. The addition reactions with imines and alkenes proceeded smoothly under proton‐transfer conditions to afford the desired products in good to high yields, and high levels of regio‐ and stereoselectivity were achieved