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ABSTRACT: Silver screen: The title reaction provides a convenient and efficient method for the construction of 5-substituted 3-trifluoromethylpyrazoles under mild reaction conditions. By using this protocol, the marketed drug Celecoxib (antiarthritic) could be easily synthesized (see scheme; DMF=N,N-dimethylformamide).
Angewandte Chemie International Edition 04/2013; · 13.45 Impact Factor
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ABSTRACT: Key to success: The title reaction provides facile access to enantioenriched 3,4-dihydroquinazolin-2(1H)-ones containing a quaternary stereogenic center in high yields with excellent enantioselectivities. Subsequent transformations lead to the convenient preparation of the anti-HIV drug DPC 083 and N-fused polycyclic compounds without loss of enantiomeric excess.
Angewandte Chemie International Edition 03/2013; · 13.45 Impact Factor
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ABSTRACT: A facile one-pot sequential conjugate addition/dearomative fluorination transformation of isoxazol-5(4H)-ones with nitroolefins and N-fluorobenzenesulfonimide (NFSI) has been developed. By using bifunctional chiral tertiary amino-thiourea catalyst, a series of chiral fluorinated isoxazol-5(4H)-ones containing one fluorine-substituted quarternary stereocenter were obtained in high yields with high enantio- and diastereoselectivities. Further transformation of adducts could afford isoxazolidin-5-one derivatives with three contiguous stereocenters.
The Journal of Organic Chemistry 12/2012; · 4.45 Impact Factor
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ABSTRACT: A highly efficient, organocatalytic, enantioselective Strecker reaction of cyclic N-acyl ketimines was developed for the preparation of enantioenriched cyclic α-amino nitriles with a quaternary carbon stereocentre and anti-HIV drug DPC 083.
Chemical Communications 10/2012; · 6.17 Impact Factor
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ABSTRACT: Trifluoroethylation made easy: The ease of execution of the reaction, which runs under mild conditions and without the need for additional base or ligands, allows for the rapid parallel synthesis of a broad variety of trifluoroethylated alkynes. Both experimental and theoretical analyses indicate that the trifluoromethylcarbene could undergo concerted insertion into the C(sp) H bond of the alkyne.
Angewandte Chemie International Edition 05/2012; 51(25):6227-30. · 13.45 Impact Factor
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ABSTRACT: The direct asymmetric three-component reaction of an aromatic (or cinnamic) aldehyde, an amine and a phosphite was investigated
by employing chiral Brønsted acid. In general, modest to good enantioselectivities (31%–87% ee) could be obtained in acceptable
isolated yields (61%–91%) for a series of substrates.
Keywordsα-aminophosphonate-organocatalysis-aromatic aldehyde-three-component reaction-enantioselectivity
Chinese Science Bulletin 04/2012; 55(17):1729-1731. · 1.32 Impact Factor
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ABSTRACT: We developed a facile, one-pot, multistep transformation between glycine imine and exocyclic α,β-unsaturated ketones in reactions catalyzed by chiral phase-transfer catalysts (PTC). A series of polycyclic imines containing three adjacent stereocenters were obtained in good to high yields with high diastereo- and enantioselectivities. Further transformation of the imines could afford N-fused polycyclic compounds with four adjacent stereocenters.
The Journal of Organic Chemistry 04/2012; 77(9):4209-16. · 4.45 Impact Factor
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ABSTRACT: We disclose an organocatalyzed enantioselective decarboxylative ketone aldol reaction of β-ketoacids with trifluoromethyl ketones in the presence of biscinchona alkaloid (DHQD)(2)AQN, affording chiral tertiary alcohols in up to 98% yield and 90% ee.
Chemical Communications 04/2012; 48(36):4308-10. · 6.17 Impact Factor
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ABSTRACT: A new organocatalytic one-pot multistep transformation via Knoevenagel condensation/aza-Michael addition/electrophilic fluorination has been developed. Simple starting materials were used under mild conditions to construct fluorinated 2,3-dihydroquinolin-4(1H)-one derivatives in good to high yields (up to 98%) and diastereoselectivities (dr up to 99/1).
The Journal of Organic Chemistry 03/2012; 77(5):2398-406. · 4.45 Impact Factor
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Chemical Science. 01/2012; 3(10):3053-3057.
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ABSTRACT: An efficient, catalytic, and enantioselective 1,2-addition of terminal 1,3-diynes to aromatic ketones was realized in the presence of 10 mol% of a Cu(OTf)(2)-hydroxycamphor-sulfonamide complex, affording chiral tertiary alcohols in up to 94% yield and 90% ee.
Chemical Communications 11/2011; 47(48):12873-5. · 6.17 Impact Factor
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Angewandte Chemie International Edition 09/2011; 50(40):9442-6. · 13.45 Impact Factor
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Angewandte Chemie International Edition 06/2011; 50(26):5869-72. · 13.45 Impact Factor
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Angewandte Chemie International Edition 04/2011; 50(15):3538-42. · 13.45 Impact Factor
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Chemical Reviews 02/2011; 111(2):455-529. · 40.20 Impact Factor
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ABSTRACT: An efficient, catalytic, diastereo- and enantioselective conjugate addition of N-(diphenylmethylene)glycine tert-butyl ester to β-aryl substituted enones was realized in the presence of 1 mol% of newly desired dinuclear N-spiro-ammonium salts, affording functionalized α-amino acid derivatives in 57-98% yields with high diastereoselectivity (up to 99:1 dr) and enantioselectivity (up to 96.5:3.5 er).
Chemical Communications 02/2011; 47(5):1631-3. · 6.17 Impact Factor
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Advanced Synthesis & Catalysis 10/2010; 352(16):2773 - 2777. · 6.05 Impact Factor
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ABSTRACT: A general method for the one-pot, three-component Strecker reaction of ketones was developed using Brønsted acids as organocatalysts. A series of alpha-aminonitriles were obtained in good to excellent yields (79-99%). A preliminary extension to a catalytic enantioselective three-component Strecker reaction of ketones (up to 40% ee) is also described.
Organic & Biomolecular Chemistry 03/2010; 8(6):1399-405. · 3.70 Impact Factor
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Angewandte Chemie International Edition 03/2010; 49(15):2772-6. · 13.45 Impact Factor
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ABSTRACT: Simple bifunctional thioureas, derived from the commercially available saccharides and chiral diamines, have been shown tunably to promote Michael-type addition of ketones to alpha,beta-gamma,delta-nitrodienes. The Michael adducts were obtained in good yields albeit with high enantioselectivites (84-99% ee). Furthermore, these products can be readily transformed into more useful molecules.
The Journal of Organic Chemistry 02/2010; 75(5):1402-9. · 4.45 Impact Factor