测试了十种不同的方法(方法A–J)来制备带有庞大烷基的叔胺。尤其是在三氟甲磺酸1-金刚烷基酯的帮助下,仲胺的S N 1烷基化(方法D)和N的反应-氯二烷基胺与有机金属试剂(方法H)的结合,但后者试剂对亚胺盐的攻击(亚胺的N-烷基化在原位生成的亚胺盐)(方法J)导致三烷基胺具有前所未有的空间拥堵。这些产物显示出绕C–N键旋转的限制。因此,旋转异构体的平衡在NMR时间尺度上很慢,导致在室温下可区分出一组NMR数据。此外,当在甲苯中加热以形成烯烃和仲胺时,具有大的烷基取代基的叔胺经历霍夫曼样消除。由于参与该衰变反应的趋势与氮原子周围的空间位阻程度相关,因此在环境温度下霍夫曼消除反应使叔胺的分离变得困难,
Mechanistic Studies of the Copper-Catalyzed Electrophilic Amination of Diorganozinc Reagents and Development of a Zinc-Free Protocol
作者:Matthew J. Campbell、Jeffrey S. Johnson
DOI:10.1021/ol0702829
日期:2007.4.1
mechanism for the copper-catalyzed amination of diorganozincreagents by O-benzoyl-N,N-dialkylhydroxylamines is supported by following stereochemically defined organometallics through the reaction and by employing the endocyclic restriction test. A copper-catalyzed electrophilic amination of organomagnesium compounds is also described in which the use of zinc halides has been eliminated.
The reduction by deuterium on platinum black of exo-2-norbornyl* and endo-2-norbornyl* to norbornane-2-d1 occurs with predominant retention of configuration
作者:T. Randall Lee、George M. Whitesides
DOI:10.1021/ja00001a058
日期:1991.1
platinum-catalyzed hydrogenation of (diolefin) dialkylplatinum(II) complexes (DO)PtR 2 ) on platinum black produces alkanes by reduction of the diolefin and alkylplatinum moieties; the platinum(II) is reduced to platinum(0) and becomes part of the catalyst. This paper reports and investigation of the stereochemistry of the reduction of C* bonds in heterogeneous hydrogenations, based on the adsorption of (DO)PtR