Asymmetric organocatalytic synthesis of γ-nitrocarbonyl compounds through Michael and Domino reactions

Highly enantioselective Michael reaction employing cycloheptanone and cyclooctanone as nucleophiles

An organocatalytic Michael reaction of cycloheptanone and cyclooctanone with nitrodienes and nitroolefins catalyzed by primary amine catalysts has been accomplished.

Asymmetric synthesis of pyrazoles and pyrazolones employing the reactivity of pyrazolin-5-one derivatives

The various catalytic asymmetric strategies employing organo- and metal-catalysts utilized pyrazolin-5-one derivatives for the synthesis of potentially bioactive enantiopure pyrazoles and pyrazolones are presented.

Stereoselective reaction of 2-carboxythioesters-1,3-dithiane with nitroalkenes: an organocatalytic strategy for the asymmetric addition of a glyoxylate anion equivalent

Under mild reaction conditions γ-nitro-β-aryl-α-keto esters with up to 92% ee were obtained, realizing a formal catalytic stereoselective conjugate addition of the glyoxylate anion synthon.

Catalytic enantioselective synthesis of α-nitroepoxides via aminolytic kinetic resolution

The first enantioselective synthesis of β-aryl-substituted α-nitroepoxides, exploiting an organocatalyzed aminolytic kinetic resolution (AKR), has been developed.

Asymmetric synthesis of highly functionalized tetrahydropyrans via a one-pot organocatalytic Michael/Henry/ketalization sequence

A diastereo- and enantioselective Michael/Henry/ketalization sequence to functionalized tetrahydropyrans is described. The multicomponent cascade reaction uses acetylacetone or β-keto esters, β-nitrostyrenes, and alkynyl aldehydes as substrates affording tetrahydropyrans with five contiguous stereocenters. Employing a bifunctional quinine-based squaramide organocatalyst, the title compounds are obtained in moderate to good yields (27-80%), excellent enantiomeric excesses (93-99% ee), and high diastereomeric ratios (dr > 20:1) after one crystallization.

General route for preparing β-nitrocarbonyl compounds using copper thermal redox catalysis

Using a simple copper catalyst, the alkylation of nitroalkanes with α-bromocarbonyls is now possible. This method provides a general, functional group tolerant route to β-nitrocarbonyl compounds, including nitro amides, esters, ketones, and aldehydes. The highly sterically dense, functional group rich products from these reactions can be readily elaborated into a range of complex nitrogen-containing molecules, including highly substituted β-amino acids.

Facile and promising method for michael addition of indole and pyrrole to electron-deficient trans-β-nitroolefins catalyzed by a hydrogen bond donor catalyst Feist's acid and preliminary study of antimicrobial activity

The importance of cooperative hydrogen-bonding effects has been demonstrated using novel 3-methylenecyclopropane-1,2-dicarboxylic acid (Feist's acid (FA)) as hydrogen bond donor catalysts for the addition of indole and pyrrole to trans-β-nitrostyrene derivatives. Because of the hydrogen bond donor (HBD) ability, Feist's acid (FA) has been introduced as a new class of hydrogen bond donor catalysts for the activation of nitroolefin towards nucleophilic substitution reaction. It has effectively catalyzed the Michael addition of indoles and pyrrole to β-nitroolefins under optimum reaction condition to furnish the corresponding Michael adducts in good to excellent yields (up to 98%). The method is general, atom-economical, convenient, and eco-friendly and could provide excellent yields and regioselectivities. Some newly synthesized compounds were for examined in vitro antimicrobial activity and their preliminary results are reported.

Stereoselective construction of all-carbon quaternary center by means of chiral phosphoric acid: highly enantioselective Friedel–Crafts reaction of indoles with β,β-disubstituted nitroalkenes

Chiral phosphoric acid catalyzed Friedel–Crafts reaction of indoles with β-alkoxycarbonyl-β-disubstituted nitroalkenes was achieved.

DMAP-promoted domino annulation of β-ketothioamides with internal alkynes: a highly regioselective access to functionalized 1,3-thiazolidin-4-ones at room temperature

One-pot DMAP-mediated regioselective access to functionalized 1,3-thiazolidin-4-ones has been achieved via annulation of β-ketothioamides with internal alkynes.

Synthesis of interesting β-nitrohydrazides through a thiourea organocatalysed aza-Michael addition

The synthesis of interesting β-nitrohydrazides, as the target product of our reaction, is reached for the first time under organocatalytic enantioselective conditions.

Organocatalytic 1,4-conjugate addition of ascorbic acid to α,β-unsaturated aldehydes: bio-inspired total syntheses of leucodrin, leudrin and proposed structure of dilaspirolactone

The organocatalytic additions of ascorbic acid to various α,β-unsaturated aldehydes via tandem 1,4-conjugate addition/hemiacetalization/hemiketalization were developed, which provided a rapid entry into the 5-5-5 spirodilactone cores of a family of ascorbylated natural products. Based on the described chemistry, total syntheses of leucodrin, leudrin and the proposed structure of dilaspirolactone were achieved.