Asymmetric Cyanation of Aldehydes, Ketones, Aldimines, and Ketimines Catalyzed by a Versatile Catalyst Generated from Cinchona Alkaloid, Achiral Substituted 2,2′-Biphenol and Tetraisopropyl Titanate
Full investigation of cyanation of aldehydes, ketones, aldimines and ketimines with trimethylsilyl cyanide (TMSCN) or ethyl cyanoformate (CNCOOEt) as the cyanide source has been accomplished by employing an in situ generated catalyst from cinchona alkaloid, tetraisopropyl titanate [Ti(OiPr)4] and an achiral modified biphenol. With TMSCN as the cyanide source, good to excellent results have been achieved
Octahedron-based redox molecular sieves M -PKU-1 ( M = Cr, Fe): A novel dual-centered solid acid catalyst for heterogeneously catalyzed Strecker reaction
作者:Weilu Wang、Siyu Zhang、Shixiang Hu、Duo Wang、Wenliang Gao、Rihong Cong、Tao Yang
DOI:10.1016/j.apcata.2017.05.030
日期:2017.7
Cr-PKU-1, an octahedron-based redox molecular sieve, was found to be an efficient, environmentally benign and easily recoverable catalyst for the heterogeneously-catalyzed Strecker reaction under the mild conditions. This material was evidenced to be a dual-centered solid acid with a large density of Brönsted acid (borate hydroxyl groups, B-OH) and Lewis acid sites (Cr3+), and therefore showed much
Continuous solid solutions constructed from two isostructural octahedron-based molecular sieves: preparation, acidity regulation and catalytic application in Strecker reactions
作者:Weilu Wang、Chunmei Zeng、Yao Yang、Pengfei Jiang、Wenliang Gao、Rihong Cong、Tao Yang
DOI:10.1039/c9nj04406j
日期:——
the catalytic activity became superior in the formation of α-aminonitriles. Three-fold coordinated boronatoms, despite the electron-deficient configuration, seemed unable to behave as Lewis acid centers probably due to steric hindrance against the adsorption of large organic substrates. This work illustrates, for the first time, possible application in Strecker reactions using zeolite-like solid solutions
斯特雷克反应在均相酸或碱催化体系中制备α-氨基酸和生物活性分子中具有重要的应用。作为新型的固体酸催化剂,采用熔融硼酸法制备了由两个基于八面体的分子筛构成的Al x Ga 1 - x -PKU-1(x = 0-1)固溶体,并在其中不断地调节酸度。温和条件下的非均相催化Strecker反应。铝x Ga 1- x-PKU-1在骨架中容纳了大量的布朗斯台德酸位点,并且随着Al原子的连续引入,酸密度和强度得到提高,因此在形成α-氨基腈时,催化活性变得更好。尽管缺乏电子构型,但三重配位硼原子似乎无法表现出路易斯酸中心的特性,这可能是由于空间位阻阻碍了大型有机基质的吸附。这项工作首次说明了使用类沸石固溶体在Strecker反应中的可能应用,并可能为控制多孔材料的表面酸度提供一种有效的方法和有益的参考。
Amberlyst-15 Catalysed Synthesis of N-Tosyl-α-Aminonitriles through Strecker Reaction
N-Tosyl-α-aminonitriles have been synthesised by a Strecker reaction of various N-tosyl aldimines with trimethylsilyl cyanide in the presence of catalytic amount of Amberlyst-15 polymer at room temperature under heterogeneous conditions.
Octahedra-based molecular sieve aluminoborate (PKU-1) as solid acid for heterogeneously catalyzed Strecker reaction
作者:Weilu Wang、Ying Wang、Bin Wu、Rihong Cong、Wenliang Gao、Bo Qin、Tao Yang
DOI:10.1016/j.catcom.2014.09.004
日期:2015.1
An aluminoborate (PKU-1) with octahedron-based framework was found to be a highly efficient solid acid catalyst for the rapid and convenient synthesis of α-aminonitriles from imines and TMSCN under mild reaction conditions. The catalytic active sites are related to the borate hydroxyl groups in the 18-ring structuralchannels. The borate hydroxyl groups play a critical role as Brønsted acid to protonate