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Stereochemically defined organofluorine compounds are vital to drug discovery and many applicable catalytic strategies have been introduced for accessing these entities stereoselectively. One approach entails incorporation of a fluorine atom (C-F bond formation) or an organofluorine moiety (e.g., CF

Aryl fluorosulfonates are developed as a deoxyfluorinating reagent in the transformation of primary and secondary alcohols into the corresponding alkyl fluorides. These reagents feature easy availability, low-cost, high stability and high efficiency. Diverse functionalities including aldehyde, ketone, ester, halogen, nitro, alkene, and alkyne are well tolerated under mild reaction conditions.

A Cu-catalyzed gem-bis(trifluoromethyl)olefination of α-diazo esters, using TMSCF3 as the only fluorocarbon source, has been developed and provides an exquisite method to access gem-bis(trifluoromethyl)alkenes. This unprecedented olefination process involves a carbene migratory insertion into "CuCF3 " to generate the α-CF3 -substituted organocopper species, which then undergoes β-fluoride elimination and two consecutive addition-elimination processes to give the desired products. The key to this efficient one-pot C1 -to-C3 synthetic protocol lies in the controllable double (over single and triple) trifluoromethylations of the gem-difluoroalkene intermediates.

Trisubstituted alkenyl fluorides are needed for research in biological chemistry, drug discovery, agrochemical development, and materials science. Among other applications, these entities are secondary amide bond mimics in one stereoisomeric form and induce a peptide turn in the other. Despite notable progress, however, many stereochemically defined trisubstituted fluoro-alkenes either cannot be prepared efficiently, or can be accessed in only one isomeric form. Here, we outline a general solution to this problem by first unveiling a practical, widely applicable, and catalytic strategy for stereodivergent synthesis of olefins bearing a fluoro and chloro terminus. This has been accomplished by cross-metathesis between two trisubstituted olefins, one of which is a purchasable but scarcely utilized trihalo alkene. Subsequent cross-coupling then be used to generate an assortment of trisubstituted alkenyl fluorides. The importance of the advance is highlighted by syntheses of, among others, a fluoro-nematic liquid crystal component, peptide analogs bearing an E- or a Z-amide bond mimic, and all four stereoisomers of difluoro-rumenic ester (anti-cancer).

The first catalytic method for diastereo- and enantioselective synthesis of allylic boronates bearing a Z-trisubstituted alkenyl fluoride is disclosed. Boryl substitution is performed with either a Z- or E-allyldifluoride and is catalyzed by bisphosphine/Cu complexes, affording products in up to 99 % yield with >98:2 Z/E selectivity and 99:1 enantiomeric ratio. A variety of subsequent modifications are feasible, and notable examples are diastereoselective additions to aldehydes/aldimines to access homoallylic alcohols/amines containing a fluorosubstituted stereogenic quaternary center.

Although the development of clay/polymer nanocomposites and their applications have attracted much attention in recent years, a thorough understanding of the structure and the decomposition mechanism of clay/polymer nanocomposites is still lacking. In this research, the intercalation of kaolinite (Kaol) with different alkylamines were investigated by X-ray diffracion (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetry and differential scanning calorimetry (TG-DSC). The results showed that the intercalation of Kaol/methanol compound with hexylamine (HA), dodecylamine (DA), and octadecylamine (OA) led to the expansion of the interlayer distance and resulted in the dominant basal diffraction at 2.86, 4.08, and 5.66 nm. The alky chains of HA, DA, and OA are tilted toward the Kaol surface in bilayer with an inclination angle of ~40°. The most probable mechanism function, activation energy E, and pre-exponential factor A were obtained by mutual authentication using KAS and Ozawa methods, itrative and Satava integral method. The average activation energy E of the three intercalation compounds are 104.44, 130.80, and 154.59 kJ mol−1, respectively. It shows a positive correlation with the alkyl chain length. The pre-exponential factor A was estimated to be 1.09 × 1015, 1.15 × 108, and 4.17 × 1021 s−1, respectively. The optimized mechanism function for the decomposition of alkylamine is G(α) = [(1-α) −1/3−1]2.

Crystal defects have been introduced into inherently narrow-band-gap and non-toxic Ag2Se quantum dots (QDs) via a facile and efficient thermal vibration approach during synthesis and studied by using electron holography and geometric phase analysis techniques. These crystal defects consequently demonstrated a solid possibility for tuning the optical band-gaps of Ag2Se QDs, and thereby enhancing the visible-light-driven water splitting and hydrogen evolution performance of Ag2Se QD-sensitized TiO2 photocatalysts.

The structural changes and thermal decomposition of kaolinite (Kaol) intercalation compounds during heating process limit their application in polymers which need to be heated during the preparation process. In this study, homologous compounds, namely, hexylamine (HEA) and octadecylamine (OCA), were used to intercalate Kaol to explore the effect of molecular chain length on the structural stability and thermal decomposition of intercalated compounds. After the intercalation by HEA and OCA, the expansion only occurred along the C-axis, and the basal spacing increased to 28.7 and 57.3 A, respectively. The morphology of Kaol changed remarkably, and all appeared curly. Compared with Kaol/HEA intercalation compounds, the Kaol/OCA intercalation compounds had better curling effect due to their different molecular chain length. The thermal decomposition process of Kaol/alkylamine intercalation compounds can be divided into two distinct stages. The molecules that adhered to the surface of the nanoscrolls and existed in the lumen of nanoscrolls began to deintercalate in the first step, and the other molecules that intercalated Kaol layers began to decompose in the second step. Thus, Kaol can be used as a potential carrier material, a carrier of sustained-release drug, or a carrier material for the catalyst. The reaction is regulated by controlling the temperature of the reaction.

An efficient nucleophilic difluoro(phenylsulfonimidoyl)methylation of unactivated primary alkyl bromides with PhSO(NTBS)CF2H has been developed. It is particularly remarkable that, when 1.5 equiv. of alkyl bromides are used, the substitution products are obtained in moderate to excellent yields. The prepared difluoro(phenylsulfonimidoyl)methylated alkanes can be readily transformed to gem-difluoroalkenes via base-mediated β-elimination reaction.

Unlike the facile synthesis of -monofluoromethyl alcohols by nucleophilic monofluoromethylation of epoxides, the synthesis of -difluoromethyl alcohols by nucleophilic difluoromethylation of epoxides still remains a challenge. Herein, studies on tackling this problem with PhSO(NTBS)CF2H (2; TBS=tert-butyldimethylsilyl) are reported. The preorganization of 2 and epoxides with BF3Et2O was found to be crucial for the reaction. The reaction shows excellent regioselectivity and has a broad substrate scope. The facile transformation of the ring-opened products to -difluoromethyl, -difluoromethyl, and -difluoromethylenyl alcohols demonstrates the synthetic utility of the reaction.

Terminal monofluoroalkenes are important structural motifs in the design of bioactive compounds, such as homeostasis regulators and mechanism-based enzyme inhibitors. However, it is difficult to control the stereoselectivity of known carbonyl olefination reactions, and olefin metathesis is limited to disubstituted terminal monofluoroalkenes. Although sulfoximines have been used extensively in organic synthesis, reports on their use in carbonyl olefination reactions have not appeared to date. Herein, we report highly stereoselective carbonyl monofluoroolefination with a fluorosulfoximine reagent. The potential of this method is demonstrated by the synthesis of MDL 72161 and by the late-stage monofluoromethylenation of complex molecules, such as haloperidol and steroid derivatives.