78-39-7Relevant articles and documents
Synthesis method of benzimidazole compound based on iron catalytic oxidation-reduction coupling reaction
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Paragraph 0140, (2020/10/05)
The invention belongs to the field of organic synthesis, and relates to a benzimidazole compound synthesis method based on an iron catalytic oxidation-reduction coupling reaction. According to the method, o-nitroaniline compounds and alcohol compounds are used as raw materials, and the benzimidazole compounds are generated through iron-catalyzed redox coupling reaction in the presence of an iron catalyst and a proton donor. The method provided by the invention provides a new way for the synthesis of benzimidazole drugs and pesticides. Compared with a traditional benzimidazole compound synthesis method with o-phenylenediamine compounds and carboxylic acid or carboxylic acid derivatives as raw materials, the method has the advantages that the atom utilization rate of the whole process is increased, the production cost is reduced, and waste gas, waste liquid and waste solid generated in the production process is reduced.
Ammonium Complexes of Orthoester Cryptands Are Inherently Dynamic and Adaptive
Wang, Xiang,Shyshov, Oleksandr,Han?eva?ki, Marko,J?ger, Christof M.,Von Delius, Max
supporting information, p. 8868 - 8876 (2019/06/13)
Fluxional chemical species such as bullvalene have been a valuable source of inspiration and fundamental insight into the nature of chemical bonds. A supramolecular analogue of bullvalene, i.e., a "fluxional host-guest system", in which the ensemble of a well-defined host and guest is engaged in continuous, degenerate constitutional rearrangements, is still elusive, however. Here, we report experimental and computational evidence for guest-induced dynamic covalent rearrangements in the ammonium complexes of self-assembled orthoester cryptands. This unique behavior is made possible by the ammonium guest playing a dual role: it is sufficiently acidic to initiate dynamic covalent exchange reactions at the orthoester bridgeheads, and as a hydrogen bond donor it acts as a supramolecular template, governing the outcome of a multitude of possible intra- and intermolecular rearrangement reactions. One particularly striking example of inherent dynamic behavior was observed in host-guest complex [NH4+o-Me2-2.1.1], which spontaneously rearranged into the larger and thermodynamically more stable complex [NH4+o-Me2-2.2.1], even though this process led to the formation of poor host o-Me2-1.1.1 as a consequence of the excess of one subcomponent (diethylene glycol; "1" in our nomenclature). These inherently adaptive host-guest networks represent a unique platform for exploring the interrelationship between kinetic and thermodynamic stability. For instance, as a result of optimal NH4+ binding, complex [NH4+o-Me2-2.2.1] was found to be thermodynamically stable (negligible intermolecular rearrangements over weeks), whereas computational studies indicate that the compound is far from kinetically stable (intramolecular rearrangements).
Orthoester exchange: A tripodal tool for dynamic covalent and systems chemistry
Brachvogel, Ren-Chris,Von Delius, Max
, p. 1399 - 1403 (2015/02/05)
Reversible covalent reactions have become an important tool in supramolecular chemistry and materials science. Here we introduce the acid-catalyzed exchange of O,O,O-orthoesters to the toolbox of dynamic covalent chemistry. We demonstrate that orthoesters readily exchange with a wide range of alcohols under mild conditions and we disclose the first report of an orthoester metathesis reaction. We also show that dynamic orthoester systems give rise to pronounced metal template effects, which can best be understood by agonistic relationships in a three-dimensional network analysis. Due to the tripodal architecture of orthoesters, the exchange process described herein could find unique applications in dynamic polymers, porous materials and host-guest architectures.
