92-44-4Relevant articles and documents
Identification of molecular crystals capable of undergoing an acyl-transfer reaction based on intermolecular interactions in the crystal lattice
Tamboli, Majid I.,Krishnaswamy, Shobhana,Gonnade, Rajesh G.,Shashidhar, Mysore S.
, p. 12867 - 12874 (2013)
Investigation of the intermolecular acyl-transfer reactivity in molecular crystals of myo-inositol orthoester derivatives and its correlation with crystal structures enabled us to identify the essential parameters to support efficient acyl-transfer reactions in crystals: 1)a the favorable geometry of the nucleophile (-OH) and the electrophile (C-O) and 2)a the molecular assembly, reinforced by C-H×××π interactions, which supports a domino-type reaction in crystals. These parameters were used to identify another reactive crystal through a data-mining study of the Cambridge Structural Database. A 2:1 co-crystal of 2,3-naphthalene diol and its di-p-methylbenzoate was selected as a potentially reactive crystal and its reactivity was tested by heating the co-crystals in the presence of solid sodium carbonate. A facile intermolecular p-toluoyl group transfer was observed as predicted. The successful identification of reactive crystals opens up a new method for the detection of molecular crystals capable of exhibiting acyl-transfer reactivity. Reactive crystal gazing? Characterization of functional groups in small organic molecules allows the prediction of their reactivity in solution, and often the structure of the resulting products with fairly good accuracy. This, however, is not true for reactions in the solid state. It was demonstrated that an understanding of the non-covalent interactions in molecular crystals can aid in identifying crystal structures that support chemical reactions (see figure). Copyright
Construction of Two-Component Chemically Reactive Supramolecular Assemblies-Acyl Migration Reactions in Cocrystals of Napthalene-2,3-Diol and Its Diesters
Bahadur, Vir,Gonnade, Rajesh G.,Krishnaswamy, Shobhana,Shashidhar, Mysore S.,Tamboli, Majid I.
, p. 1128 - 1134 (2021)
Reactions in solids are of contemporary interest due to applications in pharmaceutical industries to environmental sustainability. Although several reactive crystals that support chemical reactions have been identified and characterized, the same cannot be said about reactive cocrystals. Earlier we correlated the facile acyl group transfer reactions in crystals with supramolecular parameters obtained from the crystal structures. The structure-reactivity correlation revealed the requirement of proper juxtaposition of electrophile (C=O) and the nucleophile (OH) with distance (~3.2 ?) and angle (~90°) along the chain structure. The current article describes the preparation of cocrystals that are capable of supporting intermolecular acyl group transfer reactions in a group of structurally similar molecules. The cocrystals of naphthalene 2,3-diol and its corresponding diesters showed a facile solid state acyl transfer reaction, which has been well correlated with their crystal structures.
Oxygen-Free Regioselective Biocatalytic Demethylation of Methyl-phenyl Ethers via Methyltransfer Employing Veratrol- O-demethylase
Grimm, Christopher,Lazzarotto, Mattia,Pompei, Simona,Schichler, Johanna,Richter, Nina,Farnberger, Judith E.,Fuchs, Michael,Kroutil, Wolfgang
, p. 10375 - 10380 (2020/10/02)
The cleavage of aryl methyl ethers is a common reaction in chemistry requiring rather harsh conditions; consequently, it is prone to undesired reactions and lacks regioselectivity. Nevertheless, O-demethylation of aryl methyl ethers is a tool to valorize natural and pharmaceutical compounds by deprotecting reactive hydroxyl moieties. Various oxidative enzymes are known to catalyze this reaction at the expense of molecular oxygen, which may lead in the case of phenols/catechols to undesired side reactions (e.g., oxidation, polymerization). Here an oxygen-independent demethylation via methyl transfer is presented employing a cobalamin-dependent veratrol-O-demethylase (vdmB). The biocatalytic demethylation transforms a variety of aryl methyl ethers with two functional methoxy moieties either in 1,2-position or in 1,3-position. Biocatalytic reactions enabled, for instance, the regioselective monodemethylation of substituted 3,4-dimethoxy phenol as well as the monodemethylation of 1,3,5-trimethoxybenzene. The methyltransferase vdmB was also successfully applied for the regioselective demethylation of natural compounds such as papaverine and rac-yatein. The approach presented here represents an alternative to chemical and enzymatic demethylation concepts and allows performing regioselective demethylation in the absence of oxygen under mild conditions, representing a valuable extension of the synthetic repertoire to modify pharmaceuticals and diversify natural products.
Method for synthesizing 2,3-dioxynaphthalene
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Paragraph 0021; 0023; 0025; 0027; 0029; 0031; 0033; 0035, (2018/09/11)
The invention relates to a method for synthesizing 2,3-dioxynaphthalene. The method comprises the following steps: adding naphthalene, a catalyst and an auxiliary in a reaction solvent; heating to thetemperature of 30-70 DEG C while stirring; then dropwise adding hydrogen peroxide with the concentration being 30%; and reacting to obtain a 2,3-dioxynaphthalene solution. Compared with an existing process for preparing 2,3-dioxynaphthalene, the method for synthesizing 2,3-dioxynaphthalene is relatively low in cost and is environmentally friendly; a large number of acids and alkalis are requiredfor a traditional sulfonation and alkali fusion process and a large amount of acid-containing waste water caused by consumption of the large number of acids and alkalis are avoided, reaction conditions are gentle, energy consumption is low, and environmental protection is facilitated.