-Vinylthio Phthalimides (-VTPs): Modular Reagents for Vinylthio AIEgen Transfer.

Novel sulfur reagents -vinylthio phthalimides (-VTPs) have been employed as modular reagents for vinylthiolation, enabling the construction of aggregation-induced emission (AIE)-active tetraaryldivinyl sulfides (TADVSs) and diarylvinyl sulfides (DAVSs). Notably, TADVSs with sulfur insertion to ethene stators are reported as AIE luminogens (AIEgens) for the first time, and the corresponding photophysical properties and aggregated confirmation have been detailed for the demonstration of the AIE effect. A water-soluble TADVS with a quinolinium salt was prepared for cell imaging.

Divergent Synthesis of Fluorinated Alkenes, Allenes, and Enynes via Reaction of 2-Trifluoromethyl-1,3-enynes with Carbon Nucleophiles.

Herein, inorganic base KPO promoted divergent synthesis of CF-substituted allenes, cyclopentenes, alkynes, and fluorinated enynes via regioselective nucleophilic addition of carbon nucleophiles to 2-trifluoromethyl-1,3-enynes was developed. With the choice of different carbon nucleophiles, various fluorinated compounds could be obtained under KPO/DMF reaction system. When malononitriles were used as nucleophiles, CF-substituted allenes, cyclopentenes, and alkynes could be obtained, respectively.

-Thiohydroxy Succinimide Esters (NTSEs): Versatile Reagents for Selective Acyl and Acylthio Transfer.

Differentiation between similarly reactive sites in molecules represents an ongoing challenge of organic synthesis. Herein we described one kind of versatile reagents, -thiohydroxy succinimide esters (NTSEs), serving as both acyl and acylthio surrogates for the diverse synthesis of ketones, thioesters, amides, and acyl disulfides by selective cleavage of similarly reactive C-S and N-S bonds.

3,4-Bisthiolated Pyrroles: Concise Construction and Their Electronic Properties.

3,4-Bisthiolated pyrroles constitute key cores in pyrrole-based semiconductors, and their electronic properties could be improved by the bisthio groups via the -effect. Herein, a convenient method for the synthesis of 3,4-bisthiolated pyrroles has been developed through the AlCl-catalyzed thiolation/cyclization of homopropargylic azides, and cyclic voltammetry and DFT calculations indicated that the desired 3,4-bisthiolated pyrroles had higher HOMO orbital energies and lower band gaps than the parent unsubstituted 2,5-diphenylpyrrole.

3-Thiolated pyrroles/pyrrolines: controllable synthesis and usage for the construction of thiolated fluorophores.

Thiolation/cyclization of homopropargylic tosylamides allowed the selective synthesis of 3-thiolated pyrroles and pyrrolines controlled by solvents. Moreover, the desired 3-thiolated pyrroles were readily transformed to organic fluorophores benzothienopyrrole and bisthiolated boron dipyrromethene (S-BODIPY).

Enantioselective Cascade Biocatalysis for Deracemization of Racemic β-Amino Alcohols to Enantiopure (S)-β-Amino Alcohols by Employing Cyclohexylamine Oxidase and ω-Transaminase.

Optically active β-amino alcohols are very useful chiral intermediates frequently used in the preparation of pharmaceutically active substances. Here, a novel cyclohexylamine oxidase (ArCHAO) was identified from the genome sequence of Arthrobacter sp. TYUT010-15 with the R-stereoselective deamination activity of β-amino alcohol.

High throughput solid-phase screening of bacteria with cyclic amino alcohol deamination activity for enantioselective synthesis of chiral cyclic β-amino alcohols.

Objectives: To screening of bacteria with cyclic amino alcohol deamination activity for enantioselective synthesis of chiral cyclic β-amino alcohols.

Results: A new strain named Arthrobacter sp. TYUT010-15 with the (R)-selective deamination activity of cyclic β-amino alcohol has been isolated from nature via a high throughput solid-phase screening method.

-Alkynylthio Phthalimide: A Shelf-Stable Alkynylthio Transfer Reagent for the Synthesis of Alkynyl Thioethers.

A new kind of electrophilic alkynylthiolating reagent, called -alkynylthio phthalimide, is designed and synthesized herein. This electrophilic sulfenylating reagent can be easily prepared in three steps from commercially available phthalimide and corresponding silver acetylide. Furthermore, the -alkynylthio phthalimides are demonstrated to be efficient alkynylthio transfer reagents that can react with various C-nucleophiles, including β-ketoesters, aryl boronic acids, and Grignard reagents to afford a diverse range of alkynyl thioethers under mild conditions.

Synthesis of 4-Sulfenyl Isoxazoles through AlCl-Mediated Electrophilic Cyclization and Sulfenylation of 2-Alkyn-1-one O-Methyloximes.

An efficient method for the synthesis of 4-sulfenyl isoxazoles has been developed via AlCl-mediated electrophilic cyclization/sulfenylation of 2-alkyn-1-one O-methyloximes. Remarkably, N-arylsulfanylsuccinimides are employed as electrophiles for the construction of 4-arylsulfanyl isoxazoles, and 4-alkylsulfanyl isoxazoles are accessed with dialkyl disulfides as electrophiles.

Enantioselective synthesis of enantiopure β-amino alcohols via kinetic resolution and asymmetric reductive amination by a robust transaminase from Mycobacterium vanbaalenii.

Chiral β-amino alcohols are very important chiral building block for preparing bioactive compounds for use in pharmaceutical and fine chemical industries. Synthesis of chiral β-amino alcohols by transaminase is big challenging due to the strict substrate specificities and very low activity of the enzyme. In this work, a (R)-selective ω-transaminase (MVTA) from Mycobacterium vanbaalenii was employed as a biocatalyst for the first time for the synthesis of chiral β-amino alcohol via kinetic resolution and asymmetric reductive amination.

Copper(II)-Catalyzed Four-Component Oxysulfonylation/Diazenylation: Synthesis of α-Arylhydrazo-β-keto Sulfones.

A new and convenient method for one-pot synthesis of α-arylhydrazo-β-keto sulfones is developed via Cu (II)-catalyzed oxysulfonylation/diazenylation of alkenes. This four-component cascade reaction enables a series of α-arylhydrazo-β-keto sulfone derivatives accessed from readily available alkenes, sulfinates, and diazonium salts under aerobic conditions. Furthermore, the 3-sulfonyl cinnolin-4(1 H)-one skeleton is successfully constructed from the corresponding α-arylhydrazo-β-keto sulfone product under basic conditions.

AlCl-Catalyzed Intramolecular Cyclization of N-Arylpropynamides with N-Sulfanylsuccinimides: Divergent Synthesis of 3-Sulfenyl Quinolin-2-ones and Azaspiro[4,5]trienones.

Switchable ortho/ipso-cyclization of N-arylpropynamides induced with N-sulfanylsuccinimides as general sulfur reagents is reported. In the presence of MeOH, para-fluoro N-arylpropynamides exclusively undergo the ipso-cyclization to give 3-sulfenyl azaspiro[4,5]trienones. Two kinds of bioactive heterocycles, benzothieno-[3,2-b]quinoline and -[2,3-c]quinolone, have been directly and efficiently prepared from the corresponding sulfenylated products.

One pot simultaneous preparation of both enantiomer of β-amino alcohol and vicinal diol via cascade biocatalysis.

Objectives: To investigate the efficiency of a new cascade biocatalysis system for the conversion of R, S-β-amino alcohols to enantiopure vicinal diol and β-amino alcohol.

Results: An efficient cascade biocatalysis was achieved by combination of a transaminase, a carbonyl reductase and a cofactor regeneration system. An ee value of > 99% for 2-amino-2-phenylethanol and 1-phenyl-1, 2-ethanediol were simultaneously obtained with 50% conversion from R, S-2-amino-2-phenylethanol.

Intermolecular sulfenoamination of alkenes with sulfonamides and N-sulfanylsuccinimides to access β-sulfonylamino sulfides and dihydrobenzothiazines.

An acid-catalyzed intermolecular sulfenoamination reaction of alkenes is developed with sulfonamides as the nitrogen source and N-sulfanylsuccinimides as the sulfur source. This methodology provides a straightforward and general way to synthesize various β-sulfonylamino sulfides with high regio- and diastereoselectivity. The developed method was coupled with intramolecular C-N coupling in a one-pot procedure to afford a series of dihydrobenzothiazine derivatives, a kind of important heterocycle used as biologically active compounds in medicinal chemistry.

Highly efficient bioreduction of 2-hydroxyacetophenone to (S)- and (R)-1-phenyl-1,2-ethanediol by two substrate tolerance carbonyl reductases with cofactor regeneration.

Optically pure 1-phenyl-1,2-ethanediol is a very important chiral building block and intermediate in fine chemical and pharmaceutical industries. Reduction of 2-hydroxyacetophenone provides a straightforward approach to access these important compounds. In this study, two enantiocomplementary carbonyl reductases, BDHA (2,3-butanediol dehydrogenase from Bacillus subtilis) and GoSCR (polyol dehydrogenase from Gluconobacter oxydans) were discovered for the first time to convert 2-hydroxyacetophenone (2-HAP) to (R)-1-phenyl-1,2-ethanediol ((R)-PED) and (S)-1-phenyl-1,2-ethanediol ((S)-PED) with excellent stereochemical selectivity, respectively.

A high-throughput microtiter plate assay for the discovery of active and enantioselective amino alcohol-specific transaminases.

Chiral vicinal amino alcohols are important chiral building blocks and intermediates in the pharmaceutical industry. The transaminase (TAm) catalyzed kinetic resolution of racemic amino alcohols provides a straightforward approach to access these important compounds. This study describes the development of a novel microtiter plate assay to screen vicinal amino alcohol-specific TAms using a tetrazolium red-based colorimetric assay to monitor the rate of α-hydroxy ketone formation at 510 nm.

Hypoiodite-catalysed oxidative cyclisation of Michael adducts of chalcones with 1,3-dicarbonyl compounds: a facile and versatile approach to substituted furans and cyclopropanes.

Through hypoiodite catalysis, oxidative cyclisation of Michael adducts of chalcones with 1,3-dicarbonyl compounds for divergent synthesis of either furans or cyclopropanes is developed. The selective synthesis of major products is achieved depending on the use of different reaction conditions or substrates.

Characterization of Four New Distinct ω-Transaminases from Pseudomonas putida NBRC 14164 for Kinetic Resolution of Racemic Amines and Amino Alcohols.

Four uncharacterized ω-transaminases (ωTAs) from Pseudomonas putida NBRC 14164 have been identified and cloned from the pool of fully sequenced genomes. The genes were functionally expressed in Escherichia coli BL21, and the enzymes were purified and characterized. Four TAs showed highly (S)-selective ωTA activity and converted (S)-α-methylbenzylamine and pyruvate to acetophenone and L-Ala.

Synthesis of 3-Sulfenylated Coumarins: BF·EtO-Mediated Electrophilic Cyclization of Aryl Alkynoates Using N-Sulfanylsuccinimides.

A simple and efficient metal-free sulfenylation/cyclization of aryl alkynoates has been developed, obtaining various 3-sulfenylated coumarins in moderate to excellent yields. In the presence of BF·EtO, the stable and readily accessible N-sulfanylsuccinimides were employed as electrophiles to induce the 6-endo-dig electrophilic cyclization of alkynoates. The reaction using substrates bearing a methoxy group on the phenoxy ring proceeded in an exclusively distinct pathway via either ipso sulfenylcyclization or sulfenylation of the phenoxy ring depending on the different locations of the methoxy substituent.

Cloning and characterization of two distinct water-forming NADH oxidases from Lactobacillus pentosus for the regeneration of NAD.

Two uncharacterized nicotinamide adenine dinucleotide (NADH) oxidases (named as LpNox1, LpNox2) from Lactobacillus pentosus ATCC 8041 were cloned and overexpressed in Escherichia coli BL21 (DE3). The sequence analysis revealed that the two enzymes are water-forming Noxs with 64 % and 52 % identity to LbNox from Lactobacillus brevis DSM 20054. The optimal pH and temperature of the purified LpNox1 and LpNox2 were 7.

I2-Catalyzed C-O Bond Formation and Dehydrogenation: Facile Synthesis of Oxazolines and Oxazoles Controlled by Bases.

A general method for the synthesis of oxazolines and oxazoles was developed through I2-catalyzed C-O bond formation and dehydrogenation with the same oxidant, TBHP. By simply tuning reaction bases, either oxazolines or oxazoles were selectively produced from β-acylamino ketones.

Suzuki-Miyaura cross-couplings of arenediazonium tetrafluoroborate salts with arylboronic acids catalyzed by aluminium hydroxide-supported palladium nanoparticles.

Suzuki-Miyaura cross-couplings of arenediazonium salts with arylboronic acids catalyzed by highly active aluminium hydroxide-supported palladium nanoparticles catalyst have been investigated for the first time. The reactions are performed at 25 °C in MeOH without any base and ligand to afford biaryls in good to excellent yields under non-anhydrous and non-degassed conditions.

[Desorption behaviors of 4-nitrophenol on hyper-cross-linked polymer resin NDA-701].

Desorption behaviors of loaded 4-nitrophenol (4-NP) on hyper-cross-linked polymer resin NDA-701 were studied. The molar ratio of NaOH and 4-NP desorbed (M(NAOH/4-NP)) selection experiments were carried out at two different reaction temperature(303 K and 333 K). Desorption kinetics characteristic of4-NP on NDA-701 in the batch and fixed-bed mode were examined at different reaction temperature and M(NaOH/4-NP) values.