Thiosuccinimide enabled S-N bond formation to access -sulfenylated sulfonamide derivatives with synthetic diversity.

A thiosuccinimide enabled S-N cross-coupling strategy has been established for the intermolecular -sulfenylation of clinically approved sulfa drugs under additive-free conditions. This approach features simple operation, high chemoselectivity for sulfenylating the phenylamino group of sulfonamides, wide substrate scope, and easy scale production, affording -sulfenylated products in moderate to excellent yields (up to 90%). In addition, we also found that this transformation can be realized in a one-pot manner by employing readily available thiols as starting materials, and the obtained sulfonamide derivatives are capable of various late-stage functionalizations, including oxidation, arylation, benzylation, and methylation.

O1-conotoxin Tx6.7 cloned from the genomic DNA of that inhibits calcium currents.

Background: Conotoxins exhibit great potential as neuropharmacology tools and therapeutic candidates due to their high affinity and specificity for ion channels, neurotransmitter receptors or transporters. The traditional methods to discover new conotoxins are peptide purification from the crude venom or gene amplification from the venom duct.

Methods: In this study, a novel O1 superfamily conotoxin Tx6.

Substrate-Controlled Cu(OAc)-Catalyzed Stereoselective Semi-Reduction of Alkynes with MeOH as the Hydrogen Source.

A substrate-controlled stereoselective semi-reduction of alkynes with MeOH as the hydrogen source has been developed, and readily available Cu(OAc) (copper acetate) is utilized as an optimal catalyst. The detailed investigation of the mechanism revealed distinct catalytic processes for the ()- and ()-alkenes, respectively. As a result, a diversity of alkynes (including terminal, internal alkynes etc.

Piperazine-2,5-dione derivatives and an α-pyrone polyketide from Penicillium griseofulvum and their immunosuppression activity.

Four undescribed piperazine-2,5-dione derivatives designated janthinolides C-F, and an α-pyrone-containing polyketide namely trichopyrone C, were isolated from the extract of the fungus Penicillium griseofulvum along with four known products. Among them, janthinolide C represents the first naturally occured piperazine-2,5-dione analogue featuring a cleavaged piperazinedione ring with an oxime group, while the structure of janthinolide D possesses a rare N-methoxy group in natural products. Their structures and absolute stereochemistry were elucidated based on spectroscopic data, theoretical NMR and ECD calculations, Snatzke's method, and modified Mosher's method.

Amide Iridium Complexes As Catalysts for Transfer Hydrogenation Reduction of -sulfonylimine.

Sulfonamide moieties widely exist in natural products, biologically active substance, and pharmaceuticals. Here, an efficient water-soluble amide iridium complexes-catalyzed transfer hydrogenation reduction of -sulfonylimine is developed, which can be carried out under environmentally friendly conditions, affording a series of sulfonamide compounds in excellent yields (96-98%). In comparison with organic solvents, water is shown to be critical for a high catalytic transfer hydrogenation reduction in which the catalyst loading can be as low as 0.

Two new phenolic glucosides from marine-derived fungus sp.

Two new phenolic glucosides, including a new -glycoside () and a new -glycoside (), were isolated from a marine-derived fungus sp. The structures of new compounds were elucidated through interpretations of spectroscopic evidence and high-resolution electrospray ionization mass spectrometry. The hexose unit of was identified as -D-glucose by comparison with an authentic sample via HPLC after acid hydrolysis and derivatization.

Cyclometalated Iridium Complex-Catalyzed -Alkylation of Amines with Alcohols via Borrowing Hydrogen in Aqueous Media.

This paper develops a methodology for cyclometalated iridium complex-catalyzed -alkylation of amines with alcohols via borrowing hydrogen in the aqueous phase. The cyclometalated iridium catalyst-mediated -alkylation of amines with alcohols displays high activity (S/C up to 10,000 and yield up to 96%) and ratio of amine/imine (up to >99:1) in a broad range of substrates (up to 46 examples) using water as the green and eco-friendly solvent. Most importantly, this transformation is simple, efficient, and can be performed at a gram scale, showcasing its potential for industrially synthesizing -alkylamine compounds.

Structurally Diverse Meroterpenoids from a Marine-Derived sp. Fungus.

Three new meroterpenoids, asperaustins A-C (-), and seven known analogues (-) were isolated from a marine-derived sp. fungus. The structures and absolute configurations of these new compounds were unequivocally determined by extensive spectroscopic analyses and single-crystal X-ray diffraction analyses.

Phenolic C-Glycosides and Aglycones from Marine-Derived Aspergillus sp. and Their Anti-Inflammatory Activities.

A chemical investigation of the secondary metabolites of a marine-derived Aspergillus sp. led to the isolation and characterization of 13 phenolic compounds, including 10 new compounds (1-10). Seven new compounds (1-7) are unusual phenolic C-glycosides, while the other new compounds (8-10) are structurally related aglycones.

Three New Indole Diketopiperazine Alkaloids from Aspergillus ochraceus.

Asperochramides A - D (1 - 4), a new natural product and three new indole diketopiperazine alkaloids, along with seven known analogs (5 - 11), were isolated from the ethyl acetate extract of Aspergillus ochraceus. Their structures were elucidated by extensive spectroscopic analyses, ECD calculation, and single-crystal X-ray diffraction analysis. Compounds 3 and 4 represent a rare group of indole diketopiperazine alkaloid with a 3-hydroxyl-2-indolone moiety.

2-[(5,7-Dibromo-quinolin-8-yl)-oxy]-N-(2-meth-oxy-phen-yl)acetamide.

In the title compound, C(18)H(14)Br(2)N(2)O(3), an intra-molecular N-H⋯N hydrogen bond forms an eight-membered ring. The dihedral angle between the planes of the quinoline system and the benzene ring is 41.69 (1)°.