Decarboxylative Sulfonylation of Carboxylic Acids under Mild Photomediated Iron Catalysis.

Organic sulfones are an important class of chemical compounds widely used in many research fields. The direct decarboxylative sulfonylation of carboxylic acids is attractive but challenging, particularly when iron is used as a metal catalyst. Herein, we describe a photoinduced iron-catalytic method for the synthesis of sulfones directly using carboxylic acids via a radical-based decarboxylation.

Iron-Catalyzed Csp-Csp Cross-Coupling via Double Decarboxylation: One Step Synthesis of Remote Polar Alkenes.

Herein, we report an efficient photoinduced iron-catalyzed strategy for cross-couplings of alkyl carboxylic and acrylic acids, which provides a powerful tool for the synthesis of a variety of alkenes with polar functional groups. This novel synthetic methodology can also be applied to the preparation of ketones by using α-keto acids. Mechanistic experiments revealed preliminary mechanistic details.

BsLPMO10A from Bacillus subtilis boosts the depolymerization of diverse polysaccharides linked via β-1,4-glycosidic bonds.

Lytic polysaccharide monooxygenase (LPMO) is known as an oxidatively cleaving enzyme in recalcitrant polysaccharide deconstruction. Herein, we report a novel AA10 LPMO derived from Bacillus subtilis (BsLPMO10A). A substrate specificity study revealed that the enzyme exhibited an extensive active-substrate spectrum, particularly for polysaccharides linked via β-1,4 glycosidic bonds, such as β-(Man1 → 4Man), β-(Glc1 → 4Glc) and β-(Xyl1 → 4Xyl).

Metal-free C8-H functionalization of quinoline -oxides with ynamides.

The metal-free C8-H functionalization of quinoline N-oxides with ynamides is unveiled for the first time by the intramolecular Friedel-Crafts-type reaction of quinolyl enolonium intermediates generated from Brønsted acid-catalyzed addition of quinoline N-oxides to ynamides. Various quinoline N-oxides and terminal ynamides prove to be suitable substrates for this method. A one-pot protocol was then developed for the metal-free direct C8-H functionalization of quinolines.

A Hg(OTf)-Catalyzed Enolate Umpolung Reaction Enables the Synthesis of Coumaran-3-ones and Indolin-3-ones.

The potential of mercury catalysis has been extended to the arena of enolate umpolung reactions for the first time by the generation of enolonium species via Hg(OTf)-catalyzed -oxide addition to alkynes. The enolonium species formed can undergo intramolecular nucleophilic attack by hydroxyl or amino groups, leading to the synthesis of various coumaran-3-ones and indolin-3-ones.

Facile synthesis of 2-substituted benzo[]furans and indoles by copper-catalyzed intramolecular cyclization of 2-alkynyl phenols and tosylanilines.

A catalytic amount of CuCl and CsCO was employed to synthesize a variety of 2-substituted benzo[]furans and indoles by an intramolecular cyclization of 2-alkynyl phenols and tosylanilines. This protocol features mild conditions, high yields and broad substrate scope, which makes it a practical method for the synthesis of 2-substituted benzo[]furans and indoles.

Broad scope gold(i)-catalysed polyenyne cyclisations for the formation of up to four carbon-carbon bonds.

The polycyclisation of polyenynes catalyzed by gold(i) has been extended for the first time to the simultaneous formation of up to four carbon-carbon bonds, leading to steroid-like molecules with high stereoselectivity in a single step with low catalyst loadings. In addition to terminal alkynes, bromoalkynes can also be used as initiators of polyene cyclisations, giving rise to synthetically useful cyclic bromoalkenes.

Formal (4+1) cycloaddition of methylenecyclopropanes with 7-aryl-1,3,5-cycloheptatrienes by triple gold(I) catalysis.

7-Aryl-1,3,5-cycloheptatrienes react intermolecularly with methylenecyclopropanes in a triple gold(I)-catalyzed reaction to form cyclopentenes. The same formal (4+1) cycloaddition occurs with cyclobutenes. Other precursors of gold(I) carbenes can also be used as the C1 component of the cycloaddition.