Channel: Reviews http://sioc-journal.cn/Jwk_yjhx EN-US http://sioc-journal.cn/Jwk_yjhx/EN/0253-2786/current.shtml http://sioc-journal.cn/Jwk_yjhx 0253-2786 http://sioc-journal.cn/Jwk_yjhx/EN/10.6023/cjoc202110027 Transition metal-catalyzed C—H functionalization is an effective method for constructing C—X (X=O, N, F, I, …) bonds, which plays a crucial role not only in traditional organic synthesis, pesticides and medicine areas, but also in generating skeletons of biologically active natural products containing C—X heterocycles. Due to its high reaction efficiency, good atomic economy and environmental friendliness, palladium-catalyzed C—H functionalization has been demonstrated as one of the focus topics in the field of transition metal-catalyzed construction of C—X bonds for decades. Based on previous experimental results, density functional theory (DFT) has been employed to study the palladium-catalyzed C—H functionalization for constructing C—X bonds in detail, for obtaining more information about reaction process, such as microscopic reaction mechanism and selectivity regulation principles, and thus inspire new ideas for improving the selectivity and reactivity of palladium-catalyzed C—H functionalization in constructing C—X bonds. Herein, the latest density functional theory research results on palladium-catalyzed C—H functionalization in constructing C—X (X=O, N, F, I, …) bonds are summarized, with emphasis on the corresponding computational results about microcosmic reaction mechanism and selectivity controlling. The present issues and prospects of future development in this field are also summarized and forecasted in the end.

]]> http://sioc-journal.cn/Jwk_yjhx/EN/10.6023/cjoc202110028 Transition-metal catalyzed directed C—H bond activation and cyclization of unsaturated molecules have been developed as an efficient method to synthesize complex carbon aromatic and heteroaromatic compounds. However, additional stoichiometric oxidants are often required to realize the reoxidation cycle. Electrochemical organic synthesis can use current to replace expensive and toxic oxidants. It is an environment-friendly synthesis method. In recent years, remarkable progress has been made in the combination of electrochemical organic synthesis and C—H activation catalyzed by transition metals (such as Pd, Ni, Co, Ru, Cu, Rh, Ir, etc.). The latest progress of transition-metal catalyzed electrooxidative annulation of unsaturated molecules such as alkynes, olefins, carbon monoxide and isocyanogens via directed C—H activation is reviewed. Finally, the challenges and the future development on this important area are also described.

]]> http://sioc-journal.cn/Jwk_yjhx/EN/10.6023/cjoc202111019 Nitrogen-nitrogen bonds are widely found in drugs, nature products and organic materials. Design and synthesis of nitrogen-nitrogen motifs with high efficiency have always been an important issue in organic chemistry. The nitrogen sources such as amines, nitriles, nitroso, and azides or other N-functionalized reagents, are commonly exist in organic compounds. Direct N-N coupling of these nitrogen sources provides a more convergent synthesis strategy to produce different heterocycles and hydrazines containing the N-N motif. In this paper, the intermolecular and intramolecular formation of N—N bond in recent years is reviewed, and the difficulties and future development of this method are prospected.

]]> http://sioc-journal.cn/Jwk_yjhx/EN/10.6023/cjoc202112008 Rare-earth (RE) metal-base Lewis pairs comprised of Lewis acidic RE metals and main group Lewis bases have been developed recently. Distinct from traditional reaction pathway mediated by RE metal complexes, it’s the synergistic effect between Lewis acidic RE metal center and Lewis basic center that enables the activation of incoming substrates. This kind of extraordinary Lewis pairs can split the non-polar H-H bond, as well as react with carbonyl compounds, diazo compounds, azide compounds, etc., leading to a series of unique and intriguing RE metal complexes. Meanwhile, these Lewis pairs are also applied as catalysts for polymerization of conjugated polar alkenes and hydrosilylation of carbon dioxide with excellent results. Researches mentioned above are reviewed in this paper, and new prospects for the future development of RE based Lewis pairs are put forward.

]]> http://sioc-journal.cn/Jwk_yjhx/EN/10.6023/cjoc202110036 Galectins are a family of soluble proteins which can specifically recognize the structure of β-galactoside. It is widely distributed in normal and diseased tissues, and plays an important role in cell adhesion, cell apoptosis, inflammatory response, tumor metastasis and other related processes. Galectin is a promising target for the treatment of many diseases, such as tumor, inflammation and neurological diseases. Herein, the synthesis and biological activities of small galectin inhibitors derived from D-galactose are reviewed according to the difference of derivatization sites, which are expected to provide research thought for designing galectin inhibitors with high affinity and high selectivity, and afford reference for development of new drug candidates targeting galectins.

]]> http://sioc-journal.cn/Jwk_yjhx/EN/10.6023/cjoc202112022 The microflora in the mammalian gut plays an essential role in maintaining the physiological states and pathological changes of the host, and it is of significance for host health to detect the microflora in the gut. However, the traditional staining methods for bacteria have some drawbacks, such as poor specificity, incompatibility with living cells, and susceptibility, thereby limiting further study on the morphology and function of intestinal microflora. The fluorescence imaging technique could accurately reveal the location of symbiotic, pathogenic, and opportunistic bacteria in the intestine. The fluorescence imaging technique could reflect some information, including bacterial activity, metabolic exchange, and immune interactions between the host and the microbe due to its advantages of non-invasive, less tissue damage, higher specificity, and sensitivity, thereby being widely utilized in bacterial detection. More importantly, the fluorescent-labeled probes are the critical factor in the fluorescence imaging of intestinal microflora, promoting the development of fluorescence imaging technology continuously. This review summarizes the labeling strategies designed for different intestinal microflora, including fluorescent probes and isotope probes, and disscussed the metabolic labeling, the methods of non-metabolic labeling and the specific labeling of metabolites, finally providing a prospect for the development of the fluorescent-labeled probes for intestinal microflora.

]]> http://sioc-journal.cn/Jwk_yjhx/EN/10.6023/cjoc202111001 Boron dipyrromethene (BODIPY) dyes are widely used in the fields of life sciences, chemical analysis and optoelectronic materials due to its excellent photophysical properties, favorable biocompatibility, facile synthesis and modification etc. The synthesis and derivative strategies of BODIPY provide the basis for its wide application and have attracted great attention from researchers. In this review, the modification strategies for different reaction positions of BODIPY have been discussed, and Pd-catalyzed cross-coupling reactions and oxidative coupling reactions about BODIPY are discussed individually. Finallly, the development of this field is prospected.

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