The scientists have been working on developing more efficient and green ways to synthesize organophosphorus compounds as they have broad utilities such as reagents for chemical reactions, photovoltaic materials, flame retardants, biologically active molecules and so on. The difunctionalization reactions between P-center radicals and unsaturated compounds provide powerful methods for the synthesis of organophosphorus compounds in least and concise steps. This review will summarize the recent development in this area on the basis of different types of P-centered radical initiators.

A simple and mild protocol for the copper-catalyzed decarboxylative coupling of alkenyl acids with P(O)H compounds was developed, thus providing a facile route to the vinylphosphorus compounds. Moreover, the reaction could also afford β-ketophosphorus compounds as the major products in air using oxygen as an oxidant. In addition, the remarkable features of these two types of reactions include excellent reaction chemoselectivity, good functional group tolerance and mild reaction conditions (e.g., cheap oxidant, ligand-free condition and room temperature).

A concise and efficient iodine/copper(I) iodide-mediated intramolecular oxidative C—O bond formation reaction has been developed for oxazole synthesis. Under the optimal reaction conditions, oxidative cyclization of readily accessible enamide substrates provides facile access to a variety of oxazole derivatives bearing aryl, alkyl, amide, ester, and acyl substituents.

Organo-phosphorus chemistry is an important branch of organic chemistry and life science research. P-Stereogenic organophosphorus compounds have attracted great interest due to their potential applications in the fields of pharmaceutical chemistry, agrochemistry, material science and as ligands for asymmetric catalysis. The preparation of enantiomerically enriched phosphorus compounds with P-stereogenic centers using natural chiral compounds as chiral auxiliary has received considerable attention. The recent development of the asymmetric synthesis of P-stereogenic organophosphoryl compounds employing menthol, sparteine, ephedrine, and carbohydrates as chiral auxiliary is summarized.

Recently, the fluorescent bio-probe based on water-soluble boron-dipyrromethene (BODIPY) obtains enormous progress on structural optimization and functional modification, and becomes novel high-performance biological imaging materials owing to the development of hydrophilic modification. Focusing on the methods for improving the hydrophilicity of BODIPY, the water-soluble BODIPYs have been classified as ionic probe, electrically-neutral probe and amphiphilic probe. The research progress on the application of water-soluble BODIPY dyes in field of biology and medicine since 2006 has been summarized in this review, such as detection of necessary and pathogenicbiological chemical components, early detection and intervention of cancer, labelling drug delivery, marking specific organelles, real-time monitoring of biochemical and property changes with cells, andphotodynamic therapy. The merits of methods for improving the hydrophilicity and main issues of current studies have been summed up. The hypothesis for future directions has also been put forward.

A triphenylphosphine mediated direct trifluoromethylthiolation of indolizine and pyrrole by trifluoromethanesulfonyl chloride was developed. The readily accessable reagents and transition metal-free reaction conditions allowed this protocol applicable for large scales synthesis.

A simple and rapid method is developed for the oxidation of thiols to the corresponding disulfides using N-fluorobenzenesulfonimide (NFSI) as the oxidant without any contamination by over oxidation. The synthetic protocol for disulfide bond formation proceeded efficiently under external base-and metal-free conditions with the advantages of simple operation, mild reaction conditions as well as short reaction times.

Aromatic boronic acids and esters are essential intermediates and have been widely used in biology, medicine and material science. In this paper, the resent progress on their synthesis is summarized, especially Pd-catalyzed borylation of aryl chlorides with steric hindrance substrates, other metal (Ni, Cu, Fe, Zn, Rh, Co)-catalyzed borylation, metal-free borylation, and photoinduced borylation.

Nitrogen heterocyclic compounds can be found in various natural products, pharmaceutical chemistry and material chemistry. Due to azide group linked to olefins, α-aryl vinyl azide has unique properties, which can act as electrophilic reagents, nucleophilic reagent, or radical acceptor. Diverse reaction pathways of α-aryl vinyl azide provide great opportunities to generate highly reactive intermediates with unusual or unconventional reactivities, making it possible to develop novel reaction. Recently, more and more synthetic chemists used α-aryl vinyl azide as a key three atoms synthon for the construction of diverse structurally complex N-heterocyclic compounds. This review will introduce systematically the reactivities of α-aryl vinyl azide and the developments of the recent application of α-aryl vinyl azide in nitrogen heterocycle synthesis, including mechanism, reaction characteristics and application study, thus it may be helpful for the research on nitrogen heterocycle synthesis.

Organoaluminum compounds are excellent nucleophiles for organic reactions because of their high reactivities, the high Lewis acidity of the aluminum center, and their low toxicities. Therefore, organoalanes are widely applied in cross-coupling reactions. In this paper, recent research results about the organoaluminum reagents applied in cross-coupling reactions catalyzed by palladium are reviewed, involving various reaction systems.

A novel CuI-catalyzed trifluoromethylation of non-terminal enamides was investigated. N-Arylvinyl-substituted benzamide reacted with Togni reagent in dichloroethylane to afford N-(3,3,3-trifluoro-2-arylprop-1-en-1-yl) substituted benzamide. The reaction proceeded at 90℃ in air atmosphere in the presence of base and ligands. Control experiment shows that the Togni reagent firstly released CF₃ radical in the presence of copper(I) salts and CF₃ radical selectively added to the carbon-carbon double bond of β-position of enamides.

Vinyl azides have been extensively studied in organic synthesis since 1910. As a series of important intermediates, vinyl azides have a wide range of applications in recent years, especially in the synthesis of heterocyclic compounds catalyzed by transition-metals. The progress of the construction of aza-heterocyclic compounds in the field of organic synthesis is reviewed.

The detection and fluorescent identification of some substances such as sLea/x in vivo can provide important reference for the diagnosis, treatment and prognosis of disease, molecular tracing and further research on the mechanism of related diseases. Therefore, the development and discovery of high selectivity and high sensitivity chemsensors is of great value. Due to the special structure, phenyl boronic acid compounds could interact and bind with sugar, catecholamine containing catechol structure, fluoride or alkali cyanide. So boronic acids could be develeped as fluorescence sensors selectively for related substances, while have the advantages of high selectivity, high efficiency, rapid analysis and so on. In recent years, boronic acid has been functioned with new materials such as nanoparticles and quantum dots to design novel sensors for better performance. In this paper, the recent progress in the study of boronic acid compounds in sensors is reviewed.

Iodoalkynes and diiodoalkenes are valuable intermediates used extensively for C—C, C—O and C—N bonds formation. Therefore, the development of new method for the synthesis of these compunds is desirable. In this work, a novel and switchable protocol for the synthesis of iodoalkynes and diiodoalkenes has been developed, which were formed from terminal alkynes using the same reagent system of ZnI₂ and tert-butyl nitrite in the presence or absence of triethylamine, respectively. The iodoalkyne formation is operationally simple, mild (weak base and room temperature), and tolerant of a large range of functional groups. In contrast, the diiodoalkene transformation shows interesting dependence on the electron property, and only electron-rich and neutral compounds are viable substrates. The control experiments performed suggest that iodoalkynes and diiodoalkenes are not interchangeable under a series of reaction conditions, including the optimized conditions, which can be explained by the mechanism in which both of the reactions involve a iodonium intermediate formed directly from a terminal alkyne.

Frustrated Lewis pairs (FLPs) chemistry has grown rapidly during the last decade and provided a new strategy for the activation of a variety of small molecules, such as hydrogen, olefins, alkynes, carbon dioxide, tetrahydrofuran and hydrosilane etc. The activations of these molecules have probided a new method in the utility of main group element. The structure and reactivity of FLPs are reviewed and the recent progress in activation of small molecules promoted by frustrated Lewis pairs is introduced.

o-Carboranes, as well as its derivative o-carborynes, can react with a variety of unsaturated compounds through cycloadditions and transform into various functionalized carboranes which have potential applications in many an area such as boron neutron capture therapy, catalytic systhesis and drug design. Recently, people have made remarkable achievements in the functionalization of o-carboranes and o-carborynes, especially in aspects of reaction condition optimization, selectivity controlling and reaction mechanism exploration. The most recent experimental achievements in the area of cycloaddition between o-carboranes and unsaturated compounds, alkenes, polycyclic or heterocyclic aromatics, in the past ten years are summarized. The reaction mechanisms and corresponding computational findings of o-carboryne-involved [2+2+2],[2+2+1],[2+2],[3+2],[4+2] and[5+2] cycloadditions are summarized and emphasized. Moreover, the prospects of future development in this area are discussed in the end.

The difluoromethyl functional group (CF₂H) which has strong lipophilic and electron-withdrawing properties can significantly enhance the physiological activity of organic molecules. The applications of CF₂H-containing compounds in the fields of drugs, agrochemicals and so on have attracted great attention of many research groups. Therefore, the development of effective and general methodologies for the selective incorporation of difluoromethyl groups has become one of the hotspots in the field of organic chemistry. Recently, new difluoromethylation reagents and methods that were able to efficiently incorporate the difluoromethyl group under mild conditions have been developed rapidly, that pave the way for the facile introduction of difluoromethyl group into site-specific positions of the target molecules. In this paper, we will first briefly introduce some organic molecules with different functional groups which can be difluoromethylated, and then focus on the development of the recent high-performance difluoromethylation reagents, new reactions and catalysts. Finally, we will discuss the remaining problems and challenges in this particular field.

As a kind of low toxicity, environmentally friendly, high reaction activity reagent, hypervalent iodine compounds have received the widespread attention. Acyclic diaryl iodonium salt as aryl cationic reagent, has an important application in organic synthesis. Under mild conditions, diaryl iodonium salt can react with nucleophilic reagent, which has been one of the effective means of the arylation of heteroatom. According to the classification of chemical bond formation, the application of the acyclic diaryl iodonium salt in the arylation of heteroatom (including oxygen, nitrogen, sulfur, phosphorus, etc.) is discussed and the development direction in the field is prospected.

Alkaline-earth-metal compounds have been widely concerned due to its abundant reserve and the low-cost. In recent years, alkaline-earth-metal catalysis has achieved great progress in dehydrocoupling, hydroboration, hydrophosphination, hydroamination, hydrosilylation reactions experimentally and therotically. These types of reaction and catalytic mechanism, leading to indentify the role of alkaline-earth-metal in hydrogenation and dehydrogenation reaction are summarized. These reactions, in which the metal-hydride act as active species, generally undergo the reaction pathway involving the cleavage and formation of the metal-hydride covalent bond. The reaction features and mechanisms are generally recognized accrossing to the classification and discussion of these reactions, which would provide guidance for further development of alkaline-earth-metal catalysis.

Benzynes undergo insertion reaction with C=S bond of the stable sulfur ylide through a cascade[2+2] cycloaddition and ring-opening reaction to construct a new C-S bond, producing ortho-substituted aryl-alkyl thioether derivatives in moderate to good yields.

Mono-and bisdiphenyl substituted heteroarylphosphines R-PPh₂[R=2-pyridyl (3a), 2-thienyl (3b) and 2-furyl (3c)] and Ph₂P-R'-PPh₂[R'=2,6-pyridyl (6a), 2,5-thienyl (6b) and 2,5-furyl (6c)] were synthesized. After Staudinger reaction with Me₃SiN₃, those heteroarylphosphines were converted into the heteroarylphosphinimine ligands, R-PPh₂(NSiMe₃) and (Me₃SiN)Ph₂P-R"-PPh₂(NSiMe₃). The subsequently dehalosilylation reaction with CpTiCl₃ afforded the corresponding Ti heteroarylphosphinimine halfmetallocenes as olefin polymerization catalysts. The structures of all the complexes were determined by means of ¹H NMR, ¹³C NMR and ³¹P NMR spectroscopic methods and further confirmed by single-crystal X-ray diffraction analysis. When activated with methylaluminoxane (MAO) at a ratio of Al/Ti=600 and under 0.5 MPa of ethylene, these bimetallic Ti phosphinimine complexes displayed a higher catalytic activity compared to the monometallic analogues, but resulted in polymers with bimodal molecular weight distributions. Unexpectedly, 6b produced ultrahigh M_w polyethylene at lower polymerization temperature.

In recent years, low-valence iodine-catalyzed oxidative coupling reaction has made rapid progress, providing an effective method for the construction of C—C, C—O, C—N, C—S, C—P and other chemical bonds. Compared with the transition metal-catalyzed oxidation coupling reaction, this protocol is metal-free under mild conditions. It avoids the high cost and toxicity of transition metal catalyst, which meets the requirements of green chemistry. Therefore, iodine catalysis has attracted much attention of the synthetic chemists. The research progress on low-valence iodine-catalyzed oxidative coupling from 2010 to now is summarized, and outlook of this field is also prospected.

Recently, transition metal-promoted trifluoromethylation has been developed rapidly. Starting with the types of transition metal that promote the trifluoromethylation reactions, the research progress of trifluoromethylation promoted by silver, iron, palladium, nickel, rhodium and cobalt in recent years is reviewed. Moreover, the possible mechanisms of some parts of reactions are also discussed.

Germanium-containing conjugated compounds are regarded as powerful candidates for the development of optoelectronic material. As a subclass of germanium-containing conjugated compounds and a crucial type of the heavy analogues of aromatic compounds, germanium-containing aromatic hydrocarbons (Ge-AHs) have attracted much attention and developed rapidly in recent days. According to the charge of the Ge-AHs, these species were categorized into three subclasses:neutral, anionic and cationic species. Herein, the synthetic methodology together with the reactivity of these reported Ge-AHs is summarized and the parameters used for the evaluation of the aromaticity of these compounds is highlighted. Ge-AHs and aromatic hydrocarbons share similar structural and magnetic properties. However, their major reactivity is quite different. This review will not only inspire the discovery of new structures and reactivities of Ge-Ahs, but also help to form a deeper understanding of the concept of aromaticy.

Organic boronic reagents have played a critical role in the field of organic synthesis, especially Suzuki coupling, since they were founded. In return, all kinds of transition metal (Pd, Ni, Rh, Au etc.)-catalyzed coupling reactions have given a big push for the development and application of organic boronic reagents. 2,4,6-Mesitylboronic acid was used widely in various coupling reactions, including Suzuiki reaction, aromatic C-H activation, oxidative Heck reaction, carbonlation, decarboxylation, photoredox reaction and other C-X (C-N, C-S, C-Se) bonding reaction, which was used to synthesize functional materials, ligands and drug molecules. This paper includes two aspects:(1) reviewing the application of mesityl boronic acid and its ester in coupling reaction, and (2) making our points and respecting for this field.

An efficient method for carbon-carbon bond formation via desulfurative coupling of pyrimidine thioethers/4-phenylquinoline thioethers with alkynes or arylboronic acids is described. The reaction was promoted by a cheap and stable copper salt[copper(I) acetate] and catalyzed by palladium with good yields and wild substrate scope.

A selective Hay coupling reaction of aromatic terminal acetylenes and monophosphoryl-protected diynes was developed. The polarity of Ph₂P(O) realized facile isolation of the desired unsymmetrical 1,3-diynes from by-products. The low reactivity of monophosphoryl-protected diynes reduced the oxidative homocoupling of itself and enhanced the yields of desired products. A number of aromatic terminal acetylenes and monophosphoryl-protected diynes were tolerated in this reaction, and all the corresponding unsymmetrical 1,3-diynes could be obtained in moderate to good yields. The unsymmetrical 1,3-diynes could be applied to synthesize unsymmetrical yne-diynes and cyclic polyynes.

Recently, the preparation of fluorinated compounds through difunctionalization strategies has become a hot research area in fluorine chemistry. In this work, a copper-catalyzed hydroxytrifluoromethylthiolation of arylpropynones for the synthesis of the corresponding trifluoromethylthiolated enols was developed. The copper salt and solvent are crucial to the yields of this reaction. Under optimized reaction conditions, a series of trifluoromethylthiolated enols were obtained in moderate to good yields.

The addition reaction of perfluoroalkanesulfenic acids, in-situ formed from imines, to alkynes and allenes were investigated. A series of perfluoroalkyl alkenyl sulfoxides were synthesized. Markovnikov adducts were obtained in good to excellent yields from the reactions of aryl or alkyl-substituted alkynes with perfluoroalkanesulfenic acids under mild conditions. However, the reaction of terminal alkynes containing an electron-withdrawing group afforded Michael-type adducts in good yields. The addition reaction of electron-rich allenes took place at the double bond with less steric hindrance, while the double bond connecting an electron-withdrawing group was the prior reaction site in the case of electron-deficient allenes.

A simple and versatile metal-free protocol for the synthesis of perfluoroalkyated fluorene derivatives bearing phosphonate group is achieved. The reactions proceeded via one-pot three-component condensation of indenones, fluorinated alkynylphosphonates and malononitrile under mild conditions. This protocol is highly regioselective, operationally facile and applicable to a variety of indenones in good to excellent yields.

A nickel-catalyzed direct difluoromethylation of (hetero)aryl bromides with bromodifluoromethane (BrCF₂H) is described. This reaction features high efficiency, broad substrate scope and high functional group tolerance, providing a cost-efficient and straightforward route for applications in medicinal chemistry. Preliminary mechanistic studies reveal that a nickel-based, reductive cross-coupling catalytic cycle is involved in the reaction.

Trifluoromethylthiolation/oxidation of styrenes with easiy-handling AgSCF₃ used as the trifluoromethylthiolating reagent has been described, which furnished a series of α-trifluoromethylthio acetophenons. A variety of substituted styrene could be bifunctionalized via radical process in a mixed solvent of dimethyl sulfoxide (DMSO) and CHCl₃, with potassium persulfate used as the oxidant under mild conditions. A simple and efficent method for the facile construction of various α-trifluoromethylthio acetophenons is thus demonstrated.

Two electrophilic pentafluoroethylating reagents of pentafluoroethyl(p-methylphenyl)sulfonium bis(carbometh- oxy)methylide (4a) and pentafluoroethyl(4-nitrophenyl)sulfonium bis(carbomethoxy)methylide (4b), and their reactions under mild conditions with β-ketoesters, aryl iodides and heteroaromatics are described.

Diaryliodonium salts with fluorines have potential bioactivity. Vicinal trifluoromethanesulfonate substituted diaryliodonium salts were synthesized for the purpose of studying their anti-bacterial properties aganist Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis). Firstly, their chemical structures were characterized by ¹H NMR, ¹³C NMR, ¹⁹F NMR and mass spectra. The minimum inhibitory concentration (MIC) of these compounds was tested by the micro-broth dilution method. The most active 2-((3-fluorophenyl)(((trifluoromethyl)sulfonyl)oxy)-l3-iodanyl)- phenyl trifluoromethanesulfonate (1) containing fluorine group gave the promising results for Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis) (MIC values of 16, 4 and 4 μg·mL^-1), which is significantly lower than the commercial antibacterial agent of isothiazolinones. Scanning electron microscope (SEM) analysis sugggested that the compound led to the death of bacteria. Cytotoxicity tests showed that the compound 1 as well as isothiazolinones had a slight effect on the growth of Hela cells in vitro conditions.

A dehydrative cross coupling of ketone-stabilized phosphorus ylides with the readily available allylic alcohols followed by an one-pot Wittig reaction is developed. A range of functional 1,4-dienes could be obtained in 52%~95% isolated yields in the presence of 5 mol% Pd(PPh₃) ₄ and 20 mol% B(OH) ₃. The same method can be extended to ester or nitrile-stabi-lized phosphorus ylides, affording the corresponding 1,4-dienes in moderate yields.

Organic molecules containing trifluoromethyl groups often exhibit unique physical and chemical properties, and have found extensive applications. Trifluoroacetic acid and its derivatives have advantages including low cost, ready availability and high stability. Furthermore, CO₂ is the byproduct. Therefore, trifluoroacetic acid and its derivatives are ideal trifluoromethylating reagents, and have great application potentials. The progress of trifluoromethylation reactions using trifluoroacetic acid and its derivatives as CF₃-sources is reviewed, including the reactions of C-X (X=Br and I), C-H, and C=X (X=C, O). The mechanisms are also introduced.

Using the splicing principle of combining the pharmacological group triazene with 1,3,4-thiadiazole, 15 unreported 1,3,4-thiadiazole triazene derivatives were synthesized. The structures of the compounds were determined by nucleated magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). By using the typical triazene drug dacarbazine (DTIC) and drug 5-fluorouracil (5-FU) as a reference, the activity detections of human esop-hageal cancer cells (EC109), human gastric cancer cells (MGC803), and human prostate cancer cells (PC-3) were carried out. The results showed that some compounds inhibited human gastric cancer cells (MGC803) more strongly than dacarbazine (DTIC), and the IC50 values of compounds 2-(3-methyanilino)-5-[4-(3,3-dimethyltriazol-1-yl) phenyl]-1,3,4-thiadiazole (8c), 2-(2-methoxyanilino)-5-[4-(3,3-dimethyltriazol-1-yl) phenyl]-1,3,4-thiadiazole (8f), and 2-(3,4-dichloroanilino)-5-[4-(3,3-di-methyltriazol-1-yl) phenyl]-1,3,4-thiadiazole (8l) were lower than those of 5-fluorouracil with 5.3, 6.5 and 6.3 μmol/L, respec-tively. Some compounds inhibited human prostate cancer cells (PC-3) more strongly than dacarbazine (DTIC), and the IC50 value of 8l is lower than that of 5-fluorouracil with 13.5 μmol/L.

A facile and efficient I₂O₅ promoted iodosulfonylation of alkynes for direct synthesis of (E)-β-iodovinyl sulfones is described. This procedure affords various synthetically useful β-iodosulfonyl alkenes in moderate to good yields under peroxide free conditions.

A facile approach for thioetherification of 4-hydroxycoumarins with arylsulfonyl hydrazides promoted by tetrabutylammonium iodide in the presence of hydrochloric acid was developed generating a series of 3-arylthio-4-hydroxycoumarins in 65%~94% yields. Broad scope and easy availability of substrates, simple operation and high yields of products are the advantages of this method.

The phosphaalkenes, as an important part of organophosphorus chemistry, play a very important role in the field of homogeneous catalysis and functional materials due to special properties of P=C unit. However, the difficult access to phosphaalkene compounds and their less stability have severely retarded the progress of the phosphaalkene chemistry. In this paper, the recent advances in phosphaalkenes, introducing the properties, synthetic methods, and applications of phosphaalkenes to provide some reference for related researcher are reviewed.