Palladium-Catalyzed Carbene Coupling Reactions of Cyclobutanone N-Sulfonylhydrazones.

Development of chiral ligands is the most fundamental task in metal-catalyzed asymmetric synthesis. In the last 60 years, various kinds of ligands have been sophisticatedly developed. However, it remains a long-standing challenge to develop practically useful chiral η6-arene ligands, thereby seriously hampered the asymmetric synthesis promoted by arene-metal catalysts. Herein, we report the design and synthesis of a class of readily tunable, C2 symmetric chiral arene ligands derived from [2.2]paracyclophane. Its ruthenium(II) complexes have been prepared and successfully applied in the enantioselective C-H activation to afford a series of axially chiral isoquinolones (up to 99% yield and 96% ee). This study not only lays chemists' longstanding doubts about whether it is possible to use chiral arene ligand to stereocontrol ruthenium(II)-catalyzed asymmetric C-H activation, but also opens up a new avenue to achieve asymmetric C-H activation.

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Chiral Arene Ligand as Stereocontroller for Asymmetric C-H Activation.

An efficient annulation method for the synthesis of polysubstituted dihydrofurans from 1,3-dicarbonyl compounds and maleimides is described. The reactions can afford furo[2,3-c]pyrrole derivatives with satisfactory yields. The developed strategy realizes the direct oxidative double C(sp3)-H functionalization in the presence of copper(I) salts and 2-(tert-butylperoxy)-2-methylpropane. Meanwhile, this protocol features a mild reaction condition and simple catalytic system. A reaction mechanism involving a single electron oxidation is also proposed.

Copper(I)-Catalyzed Direct Oxidative Annulation of 1,3-Dicarbonyl Compounds with Maleimides: Access to Polysubstituted Dihydrofuran Derivatives.

Borylated-conjugated polyenes are used widely as synthetic building blocks for the preparation of many biologically active molecules. Nevertheless, access to these building blocks has been limited....

Ru(0)-Catalyzed Synthesis of Borylated-Conjugated Triene Building Blocks by Cross-Dimerization and Their Use in Cross-Coupling Reactions

Ru(II)/Chiral Carboxylic Acid-Catalyzed Asymmetric [4 + 3] Annulation of Sulfoximines with α,β-Unsaturated Ketones

Ru-catalysed oxidative coupling of allylsilanes and allyl esters with activated olefins has been developed via isomerization followed by C(allyl)-H activation providing efficient access to stereodefined 1,3-dienes in excellent yields Mild reaction conditions, less expensive catalysts, and excellent regio- and diastereoselectivity ensure universality of the reaction In addition, the unique power of this reaction was illustrated by performing the Diels-Alder reaction, and enantioselective synthesis of highly functionalized cyclohexenone and piperidine and finally synthetic utility was further demonstrated by the efficient synthesis of norpyrenophorin, an antifungal agent

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Ruthenium-catalyzed formal sp 3 C–H activation of allylsilanes/esters with olefins: efficient access to functionalized 1,3-dienes

Ruthenium-catalyzed stereo- and chemoselective oxidative coupling of vinyl ketones: efficient access to (E,E)-1,6-dioxo-2,4-dienes.

Herein, we report the asymmetric Ru/cinchonine dual catalysis that provides straightforward access to enantioselective synthesis of C-3 substituted phthalides via tandem C-H activation/Michael addition cascade. The use of readily accessible and less expensive [RuCl2(p-cym)]2 and cinchonine catalyst for the one-pot assembly of chiral phthalides greatly overcomes the present trend of using highly sophisticated catalysts. The developed method provides access to both enantiomers of a product using pseudoenantiomeric cinchona alkaloids as catalysts streamlining the synthesis of phthalide in both the optically active forms.

Asymmetric Ru/Cinchonine Dual Catalysis for the One-Pot Synthesis of Optically Active Phthalides from Benzoic Acids and Acrylates.

Weakly Coordinating, Hydroxyl Directed Ruthenium Catalyzed C-H Alkylation of Ubiquitous Benzyl Alcohols with Maleimides.

An oxidative cross-coupling reaction between activated olefins and vinyl boronate derivatives has been developed for the highly stereoselective construction of synthetically useful (E,E)-1,3-dienes. The highlight of this reaction is that exclusive stereoselectivity (only E,E-isomer) was achieved from a base-free, ligand-free, and mild catalytic condition with a less expensive [RuCl2(p-cymene)]2 catalyst.

Nagabhushana C. Beeralingappa

Papers

Ruthenium-catalyzed formal sp 3 C–H activation of allylsilanes/esters with olefins: efficient access to functionalized 1,3-dienes

Ruthenium-catalyzed stereo- and chemoselective oxidative coupling of vinyl ketones: efficient access to (E,E)-1,6-dioxo-2,4-dienes.

Asymmetric Ru/Cinchonine Dual Catalysis for the One-Pot Synthesis of Optically Active Phthalides from Benzoic Acids and Acrylates.

Weakly Coordinating, Hydroxyl Directed Ruthenium Catalyzed C-H Alkylation of Ubiquitous Benzyl Alcohols with Maleimides.

Ruthenium-Catalyzed Oxidative Cross-Coupling Reaction of Activated Olefins with Vinyl Boronates for the Synthesis of (E,E)-1,3-Dienes