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
Bis(amidate)bis(amido) Titanium Complex: A Regioselective Intermolecular Alkyne Hydroamination Catalyst
作者:Jacky C.-H. Yim、Jason A. Bexrud、Rashidat O. Ayinla、David C. Leitch、Laurel L. Schafer
DOI:10.1021/jo402668q
日期:2014.3.7
o) titanium precatalyst for the anti-Markovnikov hydroamination of alkynes is reported. Hydroamination of terminal and internal alkynes with primary alkylamines, arylamines, and hydrazines is promoted by 5–10 mol % of Ti catalyst. Various functional groups are tolerated including esters, protected alcohols, and imines. The in situ generated complex shows comparable catalytic activity, demonstrating
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
Stereo- and Regioselective Gold-Catalyzed Hydroamination of Internal Alkynes with Dialkylamines
作者:Kevin D. Hesp、Mark Stradiotto
DOI:10.1021/ja109192w
日期:2010.12.29
a state-of-the-art precatalyst for the stereoselective hydroamination of internal aryl alkynes with dialkylamines to afford E-enamine products. Substrates featuring a diverse range of functional groups on both the amine (ether, sulfide, N-Boc amine, fluoro, nitrile, nitro, alcohol, N-heterocycles, amide, ester, and carboxylic acid) and alkyne (ether, N-heterocycles, N-phthalimide amines, and silyl
Zirconium-Catalyzed Intermolecular Hydroamination of Alkynes with Primary Amines
作者:Karolin Born、Sven Doye
DOI:10.1002/ejoc.201101298
日期:2012.2
A simple catalyst system generated in situ by combination of 5 mol-% [Zr(NMe2)4] and 10 mol-% of a sulfonamide catalyzes the intermolecularhydroamination of alkynes with primary amines. At elevated temperatures, hydroamination is achieved with both internal and terminal alkynes as well as with sterically demanding and less demanding primary amines. In contrast, secondary amines do not react under