Heterogeneous Ni Catalysts for N-Alkylation of Amines with Alcohols
作者:Ken-ichi Shimizu、Naomichi Imaiida、Kenichi Kon、S. M. A. Hakim Siddiki、Atsushi Satsuma
DOI:10.1021/cs4001267
日期:2013.5.3
Ni/θ-Al2O3, which suggests the cooperation of the acid–basesite of θ-Al2O3. For a series of Ni/θ-Al2O3 catalysts with different particle size, the turnover frequency (TOF) per surface Ni increases with decreasing Ni mean particle size, indicating that low-coordinated Ni species and/or metal–support interface are active sites. From these results, we propose that the active site for this reaction is metal–support
已经制备了负载在各种载体上的镍纳米颗粒(Ni / MO x),并研究了胺与醇的N-烷基化反应。在这些催化剂中,镍/θ-Al系2 Ó 3通过原位H制备2的NiO -还原/θ-Al系2 ö 3烷烃具有最高的活性,在无添加剂条件下,它是苯胺和脂族胺与各种醇(苄基和脂族醇)的烷基化反应的可重复使用的多相催化剂。伯胺被转化为仲胺,仲胺被转化为叔胺。对于苯胺与脂肪醇的反应,该催化剂比基于贵金属的最新催化剂显示出更高的周转数(TON)。机理研究表明,反应是通过氢借入机理进行的。Ni催化剂的活性取决于载体材料的性质。酸碱双功能载体比碱性或酸性载体具有更高的活性,这表明载体上的酸碱位点是必需的。2 Ó 3,这表明θ-Al的酸-碱位点的合作2 Ó 3。对于一系列的Ni /的θ-Al系2 ö 3种催化剂具有不同的颗粒大小,转换频率(TOF)每面的Ni增加随镍平均粒径,这表明低配位的Ni物种和/或金属-支撑界面是
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
Sequential Reductive Amination-Hydrogenolysis: A One-Pot Synthesis of Challenging Chiral Primary Amines
作者:Thomas C. Nugent、Daniela E. Negru、Mohamed El-Shazly、Dan Hu、Abdul Sadiq、Ahtaram Bibi、M. Naveed Umar
DOI:10.1002/adsc.201100250
日期:2011.8
Difficult-to-access chiralprimaryamines were formed in good to high yield and ee using a rare example of a one-potsynthesis from prochiral ketones (sequentialreductive amination-hydrogenloysis). As a highlight we also demonstrate a one-potreductive amination-hydrogenolysis-reductive amination (five reactions) of ortho-methoxyacetophenone resulting in the chiral diamine 1-(2-methoxyphenyl)ethy
Efficient and recyclable ruthenium catalysts were synthesized from readily available polystyrene‐ or silica‐supported phosphine ligands. Catalysts bound to the polymer support through an ether linkage showed good to excellent activity towards the N‐alkylation of primary and secondary amines to afford the alkylated products in 62–99 % yield at 120–140 °C. The supported phosphine ligand/ruthenium ratio
catalytic system is applicable to the N-alkylation of both primary and secondary amines, and only harmless water is produced as co-product. A wide variety of secondary and tertiary amines can be synthesized with high atom economy under mild and less-toxic conditions. One-pot sequential N-alkylation leading to tertiary amines bearing three different substituents is also described.