Current Organic Synthesis - Volume 18, Issue 7, 2021

Severe pressure from energy consumption and serious pollution from non-renewable resources have urged human beings to develop green and energy-efficient materials. Transparent wood, consisting of original wood channel structure filled with resins, has favorable environmental friendliness and high transparency and haze, which holds huge potential in various important fields. Herein, a brief review of the current research activities centered on the development of transparent wood is provided. This review begins with an introduction to the background of transparent wood. Next, the cellular wall structure of wood and the synthetic strategy of transparent wood (including decolorization and impregnation) are summarized. Furthermore, the functionalization of transparent wood through doping nanomaterials or modifying resins is highlighted, and the relationship between the physicochemical properties and the potential uses (like optoelectronics, building materials, and furniture decoration) of transparent wood is clarified. Finally, a brief overview of the prospects and challenges for transparent wood is provided.

Introduction: Cysteine is a versatile amino acid for selective chemical modification of proteins with both chemical and biological innovations, which plays a key role in different organic reactions. Materials and Methods: Chemical modification of proteins is a rapidly expanding area in chemical biology. Selective installation of biochemical probes has led to a better understanding of natural protein modification and macromolecular function. In other cases, such as chemical alterations, the protein function has entirely changed. This review paper considers the organic reaction of cysteine, the reactivity of this α-amino acid containing sulfur, and several methodologies are also discussed. Herein, we focused on the reaction of cysteine and its application in organic synthesis, which includes addition, condensation, substitution, oxidation, and ring-opening reactions. Results and Discussion: Hence monitoring of cysteine is pivotal through the preparation of some fluorescent probes to detect cysteine in high sensitivity. Also, a bibliometric analysis was carried out using Web of Science and Scopus databases that demonstrated significant contributions being observed in organic synthesis. Analysis of keywords revealed that research hotspots were cysteine, sensor, unclassified drug, and amino acid. Conclusion: Therefore, it seems that future research focuses on using cysteine amino acids in various fields as natural products and organic reactions. This focused review highlights the enduring utility of cysteine in protein modification and sensor preparation, with a special focus on recent innovations in chemistry and biology associated with such modifications.

β-Amino-α,β-enones or β-enamino carbonyl compounds are versatile synthons intermediates for the construction of various bio-active heterocyclic compounds and have been established as multipurpose synthetic precursors in organic syntheses and in pharmaceutical developments. In this work, we will discuss the different synthetic routes to obtain β−amino−α,β-enones or β-enamino carbonyl compounds, their reactions, and their utility in the construction of organic frameworks and heterocyclic ring systems. Structurally, β- amino-α,β-enones are attractive intermediates that syndicate the ambident behaviours of nucleophilicity and electrophilicity of enones at the same time. β-amino-α,β-enones have been known as acceptors in both 1,2- and 1,4- additions that make them good intermediate compounds for annulation to different heterocycles.

Heterocycles are the main structural motif of DNA and RNA and play a crucial role in various chemical reactions of metabolisms. Therefore, heterocyclic compounds show good physiological and pharmacological properties. Coumarin and pyrazole scaffolds are present in many commercial drug molecules and natural products. This review overviews the progress made in the synthesis and functionalization of the coumarin- pyrazole hybrid heterocycle. It also includes discussion on the possible reactive sites of heterocycles, functionalization, and mechanistic pathways to incorporate pyrazole pharmacophore unit in synthesis. Several synthesis and biological studies reveal that the combination of the coumarin-pyrazole moiety is a prominent structural motif to find lead compounds in drug discovery.

Introduction: Intercapillary research in mathematics and other pure sciences areas has always helped humanity quantify natural phenomena. Materials & Method: This article also contributes to which valency-based topological indices are implemented on tetrahedral sheets of clay minerals. These indices have been used for a long time and are considered the most powerful tools to quantify chemical graphs. Results: The atoms in the chemical compound and the bonds between the atoms are depicted as the graph’s vertices and edges, respectively. Conclusion: The valency (or degree) of a vertex in a graph is the number of edges incident to that vertex. In this article, various degree-based indices and their modifications are determined to check each types’ significance.

Introduction: In this study, the synthesis of azo-linked acridine by the reaction of dimedone and synthesized diazoaryl-(2-amino-5-(phenyl)methanone using Ag2S/RHA-MCM-41nanocomposite is reported. Materials and Methods: The synthesized catalyst was characterized by FT-IR, XRD, and SEM. According to the obtained results, Ag2S/RHA-MCM-41 nanocomposite exhibited high activity in the synthesis of azo-acridine derivatives based on desirable yields and reaction time. Products were prepared in 1.5-2 h and with 88-93% yield. In all the reactions, the catalyst could be easily removed and reused, and its catalytic activity was maintained after five uses and did not decrease significantly. The structures of all newly synthesized products were characterized by spectroscopic spectra (FT-IR, ¹H NMR, ¹³C NMR) and elemental analyses. Results and Discussion: The results of the study showed that ionic liquid [DBU]OAc (entry 8) and MCM- 41/Ag2S-RHA nanocomposite (entry 8) possessed better efficiency and shorter time than other reaction conditions. Conclusion: In this study, new azo-linked acridine derivatives were synthesized by the reaction of different azo derivatives and dimedone using MCM-41/Ag2S-RHA nanocomposite, and the reaction products were obtained in 1.5-2 h with an efficiency of 88-93%. The short reaction time and high efficiency of the obtained products indicated the high efficiency of this method. In all the reactions, MCM-41/Ag2S-RHA nanocomposite could be easily removed and reused. Its catalytic activity was maintained in the sample reaction after five runs and did not decrease significantly.