Urea postmodified in a metal–organic framework as a catalytically active hydrogen-bond-donating heterogeneous catalyst
作者:Xiao-Wu Dong、Tao Liu、Yong-Zhou Hu、Xin-Yuan Liu、Chi-Ming Che
DOI:10.1039/c3cc42531b
日期:——
New functionally diverse urea-derived MOF hydrogen-bond-donating heterogeneous catalysts were achieved via postsynthetic modification, which exhibit excellent catalytic activity and very broad substrate scopes for the FriedelâCrafts alkylation reactions.
De Novo Tailoring Pore Morphologies and Sizes for Different Substrates in a Urea-Containing MOFs Catalytic Platform
作者:Zhanfeng Ju、Shichen Yan、Daqiang Yuan
DOI:10.1021/acs.chemmater.5b03999
日期:2016.4.12
structure–catalytic property relationship, a platform of urea-containing MOFs with diverse topologies as hydrogen-bonding (H-bond) catalyst has been well established in the present work. During the construction of MOFs, we proposed a new strategy called the isoreticular functionalization approach in which the desired topological net is first considered as a blueprint, and then two predesigned functionalized
H-Bonding Organocatalysed Friedel-Crafts Alkylation of Aromatic and Heteroaromatic Systems with Nitroolefins
作者:Raquel P. Herrera、Alfredo Ricci、Gabriella Dessole
DOI:10.1055/s-2004-832844
日期:——
Catalytic amounts (10 mol%) of bis-arylureas and -thioureas promote the Friedel-Crafts alkylation with nitroolefins of aromatic and heteroaromatic N-containing derivatives. A sizeable improvement of the yields is noticed on running the reactions in the absence of solvent. When applied to indoles this protocol provides in good to excellent yields and with high selectivity the corresponding Michael adducts
generate indolyl nitroalkane 5 and pyrrolyl nitroalkane 7 in high yields using β-nitrostyrene and indole/pyrrole at room temperature in the presence of catalytic amount of iodine is reported. The short reaction times and high yields of product are noteworthy. Molecular iodine promoted Michaeladdition is operationally simple and efficient method compared to the known Lewis acids or rare earth metal
Silica Gel, an Effective Catalyst for the Reaction of Electron-Deficient Nitro-Olefins with Nitrogen Heterocycles
作者:Abdullah M. A. Shumaila、Radhika S. Kusurkar
DOI:10.1080/00397910903340694
日期:2010.8.31
The reaction of electron-deficientolefins with nitrogen heterocycles such as pyrrole and indole was examined in the presence of silica gel at room temperature under stirring at solvent-free conditions. It was found that silica gel is an effective catalyst for this conjugate addition. This work resulted in the formation of monosubstituted pyrroles selectively as a major product except in a few cases