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A series of novel 7,9-dihydrothieno[3′,2′:5,6]pyrido[2,3- d]pyrimidine-4,6(3 H,5 H)-dione derivatives were synthesized efficiently via the catalyst-free reaction of aldehyde, ethyl 2,4-dioxotetrahydrothiophene-3-carboxylate, and 2,6-diaminopyrimidine-4(3 H)-one through the sequence of deethoxycarbonylation and three-component condensation in aqueous media. This protocol featured mild reaction conditions, high yields, easy work-up, and environmentally friendly procedure. [ABSTRACT FROM AUTHOR]

A series of novel benzo[ f]thiopyrano[3,4- b]quinolin-11(8 H)-one derivatives were synthesized via the reaction of aryl aldehyde, 2 H-thiopyran-3,5(4 H,6 H)-dione, and β-naphthylamine in glacial . This protocol features mild reaction conditions, high yields, and short reaction time. [ABSTRACT FROM AUTHOR]

A solvent-free and efficient synthesis of 14-aryl-14 H-dibenzo[ a, j]xanthenes through the one-pot condensation of β-naphthol and aldehydes catalyzed by recyclable and reusable Iron(III) triflate was reported. Notably, the presented method features short reaction time, excellent yield, and simple experimental procedure. [ABSTRACT FROM AUTHOR]

Smooth as isatin! A straightforward synthesis of spirocyclic oxindole–dihydropyranones through an N‐heterocyclic‐carbene‐catalyzed [4+2] annulation of α‐bromo‐α,β‐unsaturated aldehydes or α,β‐dibromoaldehyde bearing γ‐H with isatin derivatives under mild reaction conditions is disclosed (see scheme). The concise construction, ready availability of the starting materials, avoidance of external oxidants, and the potential utilization value of final products in molecular biology and pharmacy makes this approach particularly attractive. [ABSTRACT FROM AUTHOR]

A copper-catalyzed [3+2] annulation of O-acyl ketoximes with 2-aryl malonates for the concise synthesis of 3-aryl-4-pyrrolin-2-ones has been developed. The advantage of this method lies in the use of O-acyl oximes as an internal oxidant to generate the nucleophilic enamines and electrophilic p-quinone methides concurrently. The subsequent nucleophilic addition undergoes selectively on the α-C of malonates. [ABSTRACT FROM AUTHOR]

A convenient, rapid and electrochemical one‐pot protocol was developed successfully for the preparation of pyrazolo[3,4‐b]‐quinoline derivatives. The reaction is carried out in a 25 mL three neck flask equipped with graphite electrode as anode and iron electrode as cathode (electrode area of 1 cm2) with sodium bromide as supporting electrolyte at room temperature in ethanol. Fourteen pyrazolo‐[3,4‐b]‐quinoline derivatives were synthesized by use of various aldehyde (including aryl aldehydes and aliphatic aldehydes), dimedone and 5‐amino‐3‐methyl‐1‐phenylpyrazole as substrates in good yields (76–86 %) with a constant current of 30 mA after 0.14 F/mol of electricity passed. All aimed products were characterized by IR, 1H NMR and HRMS. Notably, the presented method features ecologically sound, simple experimental procedure and good yields. [ABSTRACT FROM AUTHOR]

A novel lactate dehydrogenase gene, named lrldh, was cloned from Lactobacillus rossiae and heterologously expressed in Escherichia coli. The lactate dehydrogenase LrLDH is NADH-dependent with a molecular weight of approximately 39 kDa. It is active at 40 °C and pH 6.5 and stable in a neutral to alkaline environment below 35 °C. The kinetic constants, including maximal reaction rate (Vmax), apparent Michaelis–Menten constant (Km), turnover number (Kcat) and catalytic efficiency (Kcat/Km) for phenylpyruvic acid were 1.95 U mg−1, 2.83 mM, 12.29 s−1, and 4.34 mM−1 s−1, respectively. Using whole cells of recombinant E. coli/pET28a-lrldh, without coexpression of a cofactor regeneration system, 20.5 g l−1d-phenyllactic acid with ee above 99% was produced from phenylpyruvic acid in a fed-batch biotransformation process, with a productivity of 49.2 g l−1 d−1. Moreover, LrLDH has broad substrate specificity to a range of ketones, keto acids and ketonic esters. Taken together, LrLDH is a promising biocatalyst for the efficient synthesis of d-phenyllactic acid and other fine chemicals. [ABSTRACT FROM AUTHOR]

2,3-Diaryl quinoxaline derivatives have been efficiently synthesized by cascade, metal-free, and solvent-free reaction of aryl aldehydes with aryl 1,2-diamines initiated by N-heterocyclic carbene. Compared with reported methods, this procedure has the advantages of easy work-up, reduced energy consumption, and elimination of solvent waste, hazards, and toxicity. A group of potentially bioactive compounds has been prepared for biomedical screening. [ABSTRACT FROM AUTHOR]

A series of novel tetrazolo[1,5- a]thiopyrano[3,4- d]pyrimidine derivatives were synthesized by reaction of aryl aldehyde, 2 H-thiopyran-3,5(4 H,6 H)-dione, and 5-aminotetrazole under solvent-free conditions. The features of this procedure are mild reaction conditions, high yields, and operational simplicity. [ABSTRACT FROM AUTHOR]

Abstract: A clean aqueous Kröhnke reaction process has been accomplished via a one-pot procedure of 2-acetylpyridine with aromatic aldehyde and ammonium acetate under microwave irradiation or conventional heating conditions. This method is convenient, economic and environmental friendly. [Copyright &y& Elsevier]

A catalyst-free synthesis of 6,9-dihydro-[1,3]dioxolo[4,5- g ]thieno[3,4- b ]quinolin-8(5 H )-ones as novel analogues of podophyllotoxins was developed by a three-component reaction of aldehydes, ethyl 2,4-dioxotetrahydrothiophene-3-carboxylate and 3,4-(methylenedioxy)aniline. This methodology not only provides new chemical library for the screening of anticancer activity, but also features excellent isolated yields, short reaction time, simple work up procedure and little environmental impact. [ABSTRACT FROM AUTHOR]

An abstract of the study "N-Heterocyclic Carbene-Triggered Transition-Metal-Free Synthesis of 2,3-Disubstituted Benzofuran Derivatives" by Y. Xie and colleagues is presented.

Optimized conditions A) are highly suitable for the preparation of the important dihydropyran scaffold. [ABSTRACT FROM AUTHOR]

An alternative approach to 2,3-diarylated benzofurans (III) by virtue of the sequential catalysis of NHC and Pd from substituted 2′-bromodiphenylbromomethanes (I) and aryl aldehydes (II) is developed. [ABSTRACT FROM AUTHOR]

The reaction between various isatin derivatives and 3-aryl substituted but-2-enoic acids succeeds in high yields and with high enantiomeric excesses. [ABSTRACT FROM AUTHOR]

A series of chiral δ-lactams (III) and (V) is prepared with high enantioselectivity by NHC-catalyzed oxidative γ-aminoalkylation of carboxylic acids (II) with acylhydrazones. [ABSTRACT FROM AUTHOR]

An efficient assembly of dihydropyranone was realized via the in situ activation of α,β ‐ unsaturated carboxylic acid and the subsequent formal [3+3] reaction with 1,3 ‐ dicarbonyl compound synergistically mediated by N ‐ heterocyclic carbene and LiCl. The ready availability and high stability of the starting materials, good yields, and excellent enantioselectivity make this protocol greatly attractive in the chemistry community. More information can be found in the Communication by Changsheng Yao et   al. on page   678 in Issue 5, 2016 (DOI: 10.1002/asia.201501353). [ABSTRACT FROM AUTHOR]

A novel Co/Ag bimetallic catalyzed bicycloaddition of arylethynylanilines (I) and (IV) with isonitriles is presented. [ABSTRACT FROM AUTHOR]

In situ activation of the starting carboxylic acids renders possible a direct functionalization at the unreactive β-position. [ABSTRACT FROM AUTHOR]

An NHC-catalyzed formal [4+2] reaction of isatins with N-hydroxybenzotriazole ester of α,β-unsaturated carboxylic acids bearing γ-H to construct spirocyclic oxindole-dihydropyranones is given.

An abstract of the article "An Efficient Synthesis of [1,3]Dioxolo[4,5-g]thieno[3,4-b]quinolin-8(5H)-ones as Novel Thiazapodophyllotoxin Analogues with Potential Anticancer Activity" by T. Li and colleagues is presented.