Osmium-Promoted Transformation of Alkyl Nitriles to Secondary Aliphatic Amines: Scope and Mechanism
作者:Juan C. Babón、Miguel A. Esteruelas、Ana M. López、Enrique Oñate
DOI:10.1021/acs.organomet.0c00236
日期:2020.6.8
symmetrical and asymmetricalsecondary aliphatic amines promoted by the hexahydride complex OsH6(PiPr3)2 (1) is described, and the mechanisms of the reactions involved are established. Complex 1 catalyzes the aforementioned transformations of aryl-, pyridyl-, and alkoxy-functionalized alkyl nitriles with linear or branched chains. The formation of the secondary amines involves primary imines, primary amines
描述了由六氢化物配合物OsH 6(P i Pr 3)2(1)促进的烷基腈向对称和不对称仲脂肪族仲胺的转化,并建立了涉及的反应机理。配合物1催化具有直链或支链的芳基,吡啶基和烷氧基官能化的烷基腈的上述转化。仲胺的形成涉及伯亚胺,伯胺和仲亚胺作为有机中间体。反应在温和的条件下(甲苯,100°C和4 bar H 2)进行。1的化学计量反应与新戊腈和2-甲氧基乙腈一起使我们能够分离三氢化物氮杂亚乙烯基衍生物OsH 3 ═N═CHR}(P i Pr 3)2(R = t Bu(3),CH 2 OMe(4))。它们的形成涉及将底物的N–C三键插入不饱和四氢化物OsH 4(P i Pr 3)2(A)的Os–H键中,这是通过从六氢化合物中消除H 2产生的前体。这些三氢化物氮杂亚乙烯基物质与H 2的反应是还原腈的N-C三键的关键步骤。在没有H 2的情况下,A对氮杂亚乙烯基配体的攻击会导致其C(sp 2)–C(sp
An investigation of factors governing conformational disorder of hydrocarbon chains in the solid state
作者:M.J.M. Van Oort、G. Neshvad、M.A. White
DOI:10.1016/0022-4596(87)90020-x
日期:1987.7
factors which govern conformational disorder of the n-alkyl chains in the solid state. Many of the compounds prepared displayed solid-solid phase transitions, but the thermodynamic quantities measured suggest that the bonding and structural features of these complexes control the reversibility and limit the extent of conformational disorder of the hydrocarbon chains in the solid state.
complete study of the through-the-annulus threading of the larger calix[8]arene macrocycle with di-n-alkylammonium cations has been performed in the presence of the “superweak” TFPB counterion. Thus, it was found that such threading occurs only upon partial preorganization of the calix[8]arene macroring by intramolecular bridging. In particular, 1,5-bridged calix[8]arenes with a meta- or para-xylylene bridge
在“超弱” TFPB抗衡离子存在下,对带有二正烷基铵阳离子的较大杯[8]芳烃大环的环空穿线进行了完整的研究。因此,发现仅通过分子内桥联对杯[8]芳烃大环进行部分预组织时才发生这种穿线。特别是,带有间-或对亚二甲苯基桥(2和3)的1,5-桥杂杯[8]芳烃得到假[2]轮烷,其中一个二烷基铵轴(4a – 4e +)拧入杯[8]轮的两个子腔之一中。通过使用化学位移表面图和DFT计算进行的构象研究证明,这些子腔具有3/4圆锥的几何形状。由于其两个子腔的协同作用,相对于杯[6]主机1a,杯[8]轮2和3获得了较高的假轮烷K ass值。对杯[8]-假轮烷的动态NMR研究表明,由于螺纹模板的有效性,K ass(和ΔG ass)值与杯倒立的能垒之间存在直接关系。按照DFT计算中,内切通过将杯[8]-轮3与方向性正丁基苄基铵轴4d +穿线,观察到内烷基苄基优先于烷基苄基。
Binding of carboxylatopillar[5]arene with alkyl and aryl ammonium salts in aqueous medium
The complex formation of alkyl ammoniumsalts by water-soluble carboxylatopillar[5]arene (CP5A) in aqueous medium is reported. p-Xylene diammonium salt and a series of secondary alkyl ammoniumsalts with various alkyl groups have been prepared and investigated for complex formation. All the ammoniumsalts exhibit strong host–guest complexation with CP5A under neutral aqueous conditions. 1H NMR, 1H
报道了水溶性羧化萘并[5]芳烃(CP5A)在水性介质中络合形成烷基铵盐的现象。已经制备了对二甲苯二铵盐和一系列具有各种烷基的仲烷基铵盐,并研究了其形成络合物的方法。在中性水溶液条件下,所有铵盐均表现出与CP5A强烈的主客体络合。1 H NMR,1已经进行了H DOSY和2D NOESY NMR实验来表征这些包合物。在这项研究中,疏水和静电相互作用控制了络合物的形成,从而导致假轮烷物种的形成。获得了五个假[2]轮烷和一个假[3]轮烷,其缔合常数值和化学计量通过NMR滴定法进行了评价。结果表明,铵盐作为水性介质中CP5A的新型互补合成子的用途,增加了现有识别基序的种类,例如百草枯和1,4-双(吡啶)衍生物。
Threading the Calix[5]arene Annulus
作者:Giuseppe Gattuso、Anna Notti、Melchiorre F. Parisi、Ilenia Pisagatti、Maria E. Amato、Andrea Pappalardo、Sebastiano Pappalardo
DOI:10.1002/chem.200902945
日期:2010.2.22
Slowly does it! Di‐n‐alkylammoniumions (such as 2⋅H+) thread the annulus of calix[5]arene 1 to yield stable [2]pseudorotaxanes. The ease of formation of this hitherto unknown family of interpenetrated supermolecules is predominantly determined by salt ion‐pairing effects, whereas the time course of the threading/dethreading process depends on the length of the cation alkylammonium chains.