Readily accessible α,α-diarylprolinols have been recently exploited as useful organocatalysts in different asymmetric reactions. It has proposed that they operate either via bifunctional activation of the reactive partners through non-covalent interactions or formation covalent enamine and iminium intermediates. This feature article describes employment catalysts epoxidation α,β-enones, aldol reaction, cycloaddition, carbon–carbon carbon–heteroatom bond forming

An operationally simple and mild protocol for the catalytic enantioselective epoxidation of α,β-unsaturated ketones has been estabilished using commercially available α,α-diphenyl-l-prolinol as bifunctional organocatalyst tert-butyl hydroperoxide (TBHP) oxidant. The epoxides have obtained in good yields with up to 80% ee.

The desymmetrization of N-acylaziridines with Me3SiSPh, catalyzed by commercially available (R) and (S)-VAPOL hydrogen phosphate, produced β-(N-acylamino)phenylthioethers in a highly enantioselective efficient manner (78−99% ee). selection the suitable aziridine/nucleophile/catalyst molar ratio is crucial to obtain high ee's.

The enantioselective α-heterofunctionalization of α-substituted 1,3-dicarbonyl compounds is an attractive area organic chemistry, thanks to the undoubted value final as versatile intermediates for synthesis natural products and pharmaceutical targets. In this context, organocatalytic approach gaining importance, alongside asymmetric metal-based catalysis, production molecules with highly functionalized chiral quaternary stereocenters containing a carbon-heteroatom bond. This review aims...

Abstract An efficient and convenient highly enantioselective Michael addition of malononitrile to enones has been developed by using quinine as the organocatalyst. The adducts were isolated in excellent yield high asymmetric induction (up 95% ee ). easy route difficultly accessible ester derivatives also disclosed.

The stereoselective synthesis of highly functionalized tetrahydrothiophenes bearing three contiguous stereocenters, one them quaternary, can be achieved by reacting trans-α-cyano-α,β-unsaturated ketones and trans-tert-butyl 4-mercapto-2-butenoate in the presence a readily available amine thiourea. products are obtained high yield, good diastereoselectivity, excellent enantioselectivity. overall formation occurs via cascade double Michael reaction involving efficient process dynamic kinetic...

A dramatic enhancement of the diastereo- and enantioselectivity in nitro-Michael addition reaction organocatalysed by a commercially available α,α-L-diaryl prolinol was disclosed when performing unconventional hexafluorobenzene as medium. DFT calculations were performed to clarify origin stereoselectivity role C(6)F(6).

Abstract An efficient cyclopropanation, by a Michael‐initiated ring‐closing (MIRC) reaction of 2‐arylidene‐1,3‐indandiones and 2‐arylidene malononitriles, has been developed using different α‐monohalogenated methylene active compounds with triethylamine. The first enantioselective cyclopropanation to spirocyclopropanes derived the dimethyl bromomalonate commercially available α,α‐ L ‐diarylprolinol as organocatalyst K 2 CO 3 additive accomplished. were isolated in high yield up 85 % ee ....

Abstract The asymmetric epoxidation of α,β‐enones by the readily available bis(3,5‐dimethylphenyl)‐( S )‐pyrrolidin‐2‐ylmethanol and tert ‐butyl hydroperoxide (TBHP) is described. Stereoelectronic substitution on aryl moiety diaryl‐2‐pyrrolidinemethanols was found to significantly affect efficiency with respect previously reported ( )‐diphenyl‐2‐pyrrolidinemethanol. Improved reactivity enantioselectivity were achieved at reduced catalyst loading (20 mol %) ees up 94% for chalcone epoxides...

The first diastereospecific and enantioselective epoxidation of trans-2-aroyl-3-arylacrylonitriles by means the commercially available diaryl l-prolinol/tert-butyl hydroperoxide system has been developed. These diversely functionalized epoxides were obtained in excellent yield (up to 99%), complete diastereoselectivity for trans-isomer, good enantioselectivity 84% ee). Highly enantioenriched can be easily after a single crystallization (ee > 90%).

A high-yielding and enantioselective access to novel N-Boc terminal aziridines, bearing a quaternary stereogenic center, has been developed via an aza-Michael initiated ring-closure (aza-MIRC) reaction of α-acyl acrylates with N-tosyloxy tert-butyl carbamate catalyzed by chiral amino thiourea. The feasibility the aziridine regioselective ring-opening valuable α,α-disubstituted α-amino acid esters demonstrated.

The first enantioselective epoxidation of readily available alkylidenemalononitriles has been developed by using a multifunctional cinchona derived thiourea as the organocatalyst and cumyl hydroperoxide oxidant. A new simple one-pot asymmetric epoxidation/SN2 ring-opening reaction with 1,2-diamines leading to important enantioenriched heterocycles, i.e. 3-substituted piperazin-2-ones, established.

Readily available chiral amine–thioureas are effective catalysts for the first diastereo- and enantioselective epoxidation of unsaturated pyrazolones. The trans- or cis-spiroepoxides preferentially obtained in good yield high to excellent enantioselectivity using an appropriate organocatalyst tert-butyl hydroperoxide as oxidant. appears applicable highly challenging β,β′-substituted pyrazolones, giving access spiroepoxides bearing two vicinal quaternary stereocenters. reaction represents a...

A one-pot enantioselective route to N-unprotected 2,3-dihydro-1,5-benzothiazepinones, by an organocatalyzed sulfa-Michael reaction of readily available α,β-unsaturated N-acyl pyrazoles with 2-aminothiophenols followed silica-gel-catalyzed lactamization, has been developed. The method proceeds under mild conditions at room temperature and it requires only 1 mol % catalyst loading, give 2-aryl/alkyl-substituted 1,5-benzothiazepines in generally good excellent yields enantioselectivities....

A one-pot Knoevenagel reaction/asymmetric epoxidation/domino ring-opening cyclization (DROC) has been developed from commercial aldehydes, (phenylsulfonyl)acetonitrile, cumyl hydroperoxide, 1,2-ethylendiamines, and 1,2-ethanol amines to provide 3-aryl/alkyl piperazin-2-ones morpholin-2-ones in yields of 38 90% up 99% ee. Two out the three steps are stereoselectively catalyzed by a quinine derived urea. The sequence applied for short enantioselective entry key intermediate, both absolute...

The Cover Feature depicts an asymmetric one-pot synthesis of mandelic acid derivatives. A bifunctional organocatalyst selectively promotes two reactions leading to enantioenriched 1-cyano-1-phenylsulfonyl epoxides, which undergo water-mediated ring-opening and then hydrolysis in a cascade process, yielding the products with high efficiency enantioselectivity. cover art shows synthetic sequence intermediates formed from atop waterfall, highlighting role water crucial steps. More information...

alpha‐Angelica lactone is a five‐membered heterocycle belonging to the rich family of butenolides, key motif present in great variety bioactive and natural products. Moreover, it small compound attainable from platform molecule levulinic acid, which turn readily accessible lignocellulosic biomass. These important features contributed arouse interest a‐angelica over last years. Beyond its upgrading added value products, such as g‐valerolactone, polymers, biofuels, has been identified...

In this article the first enantioselective epoxidation reaction of acyclic and cyclic 2-arylidene-1,3-diketones is reported. Easily accessible or commercially available alpha,alpha-diaryl prolinols as organocatalysts in presence tert-butyl hydroperoxide (TBHP) provide corresponding epoxides high to excellent yield (up 99%) up 85% ee (ee >90% after crystallisation). These are pharmaceutically important building blocks intermediates for synthesis densely functionalised epoxide derivatives.