Environmentally friendly one-pot synthesis of α-alkylated nitriles using hydrotalcite-supported metal species as multifunctional solid catalysts
Environmentally friendly one-pot synthesis of α-alkylated nitriles using hydrotalcite-supported metal species as multifunctional solid catalysts
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DOI：
10.1002/chem.200600317
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发表时间：
2006-11-06
影响因子：
4.3
通讯作者：
Kanedar, Kiyotomi
中科院分区：
文献类型：
--
作者：
Motokura, Ken;Fujita, Noriaki;Kanedar, Kiyotomi
分别用RuCl3中心点NH(2)O和K-2[PdCl4]溶液处理碱性层状双氢氧化物水滑石(HT，Mg6Al2(OH)(16)CO3)，制备了Ru接枝水滑石(Ru/HT)和水滑石负载钯纳米粒子(Pd-Nano/HT)。通过X射线衍射、能量色散X射线、电子顺磁共振和X射线吸收精细结构能谱分析，证明了单体Ru-IV接枝到了HT膜的表面。同时，经过表面隔离的Pd-II物种还原后，通过透射电子显微镜分析，在Pd-Nano/HT表面观察到高度分散的Pd纳米团簇，平均直径约为70埃。这些水滑石负载的金属催化剂可以通过金属催化的氧化还原和羟色胺的碱位促进的Aldol反应，有效地促进各种腈与伯醇或羰基化合物的a-烷基化反应。在这些催化α-烷基化反应中，均一碱是不必要的，唯一的副产物是水。此外，这些催化剂体系还适用于戊二腈衍生物的一锅合成法。
A ruthenium-grafted hydrotalcite (Ru/HT) and hydrotalcite-supported palladium nanoparticles (Pd-nano/ HT) are easily prepared by treating basic layered double hydroxide, hydrotalcite (HT, Mg6Al2(OH)(16)CO3) with aqueous RUCl3 center dot nH(2)O and K-2[PdCl4] solutions, respectively, using surface impregnation methods. Analysis by means of X-ray diffraction, and energy-dispersive X-ray, electron paramagnetic resonance, and X-ray absorption fine structure spectroscopies proves that a monomeric Ru-IV species is grafted onto the surface of the HT. Meanwhile, after reduction of a surface-isolated Pd-II species, highly dispersed Pd nanoclusters with a mean diameter of about 70 angstrom is observed on the Pd-nano/HT surface by transmission electron microscopy analysis. These hydrotalcite-supported metal catalysts can effectively promote a-alkylation reactions of various nitriles with primary alcohols or carbonyl compounds through tandem reactions consisting of metal-catalyzed oxidation and reduction, and an aldol reaction promoted by the base sites of the HT. In these catalytic alpha-alkylations, homogeneous bases are unnecessary and the only by-product is water. Additionally, these catalyst systems are applicable to one-pot syntheses of glutaronitrile derivatives.