112207-03-1Relevant academic research and scientific papers
Construction of quaternary stereocenters by nickel-catalysis of asymmetric Michael reactions
Christoffers, Jens,Roessler, Ulrich,Werner, Thomas
, p. 701 - 705 (2000)
Quaternary stereocenters were constructed with an enantio-selectivity of up to 91‰ ee under aerobic conditions and at ambient temperature in the Michael reaction of β-dicarbonyl compounds and methyl vinyl ketone with Ni(OAc)2·4H2O an
Enantioselective organocatalytic diels aminations: α-aminations of cyclic β-keto esters and β-keto lactones with cinchonidine and cinchonine
Pihko, Petri M.,Pohjakallio, Antti
, p. 2115 - 2118 (2004)
Catalytic enantioselective α-amination reactions of β-keto esters and β-keto lactones with dibenzyl azodicarboxylate are catalyzed by cinchona alkaloids, affording the products in up to 99% yield and 90% ee.
A Simple and Efficient Method for Transesterification of β-Ketoesters Catalysed by Iodine
Chavan, Subhash P.,Kale, Ramesh R.,Shivasankar,Chandake, Sanjay I.,Benjamin, Swapnanjali B.
, p. 2695 - 2698 (2003)
A facile transesterification of β-ketoesters using catalytic iodine is described.
Facile and selective transesterification of β-keto esters using NaIO4, KIO4, and anhydrous CaCl2 as inexpensive catalysts under neutral conditions
Bandgar, Babasaheb P.,Hashmi, Arshad M.,Pandit, Shivaji S.
, p. 1101 - 1104 (2005)
NaIO4, KIO4 and anhydrous CaCl2 catalyzed selective transesterification of β-keto esters is described. Neutral reaction conditions and inexpensive catalysts are important features of this method.
Recyclable Hypervalent-Iodine-Mediated Dehydrogenative Cyclopropanation under Metal-Free Conditions
Duan, Ya-Nan,Zhang, Zhao,Zhang, Chi
supporting information, p. 6176 - 6179 (2016/12/09)
A method is developed for the synthesis of cyclopropanes from the C(sp2)-C(sp3) single bonds of β-keto esters with activated methylene compounds under metal-free conditions in the presence of 5-trimethylammonio-1,3-dioxo-1,3-dihydro-1λ5-benzo[d][1,2]iodoxol-1-ol anion (AIBX), a recyclable water-soluble hypervalent iodine(V) reagent developed by our group. This mild, efficient method has a wide substrate scope and good functional group tolerance and is complementary to existing cyclopropanation strategies. The method can be used to construct polysubstituted ring-fused cyclopropanes and is amenable to further synthetic transformations for construction of complex biologically active molecules as well as asymmetric cyclopropanes (90% de) when a chiral ester auxiliary is used.
Substrate range of the titanium TADDOLate catalyzed asymmetric fluorination of activated carbonyl compounds
Bertogg, Andreas,Hintermann, Lukas,Huber, Dominique P.,Perseghini, Mauro,Sanna, Maria,Togni, Antonio
experimental part, p. 353 - 403 (2012/05/07)
The substrate range of the [TiCl2(TADDOLate)] (TADDOL=α,α,α′,α′-tetraaryl-1,3-dioxolane-4, 5-dimethanol)-catalyzed asymmetric α-fluorination of activated β-carbonyl compounds has been investigated. Optimal conditions for catalysis are characterized by using 5 mol-% of TiCl2(naphthalen-1- yl)-TADDOLate) as catalyst in a saturated (0.14 mol/l) MeCN solution of F-TEDA (1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis- [tetrafluoroborate]) at room temperature. A series of α-methylated β-keto esters (3-oxobutanoates, 3-oxopentanoates) with bulky benzyl ester groups (60-90% ee) or phenyl ester (67-88% ee) have been fluorinated readily, whereas α-acyl lactones were also readily fluorinated, but gave lower inductions (13-46% ee). Double stereochemical differentiation in β-keto esters with chiral ester groups raised the stereoselectivity to a diastereomeric ratio (dr) of up to 96.5:3.5. For the first time, β-keto S-thioesters were asymmetrically fluorinated (62-91.5% ee) and chlorinated (83% ee). Lower inductions were observed in fluorinations of 1,3-diketones (up to 40% ee) and β-keto amides (up to 59% ee). General strategies for preparing activated β-carbonyl compounds as important model substrates for asymmetric catalytic α-functionalizations are presented (>60 examples). Copyright
SPIROCYCLIC COMPOUNDS AS MODULATORS OF CHEMOKINE RECEPTOR ACTIVITY
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Page/Page column 42-43, (2011/04/26)
The present application describes modulators of chemokine receptor activity of formula (I) or stereoisomers or pharmaceutically acceptable salts thereof. In addition, methods of treating and preventing inflammatory diseases such as asthma and allergic diseases, as well as autoimmune pathologies such as rheumatoid arthritis and transplant rejection using modulators of formula (I) are disclosed.
2-mercaptocyclopentanecarboxylic acid compounds, a process for their preparation and pharmaceutical compositions containing them
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, (2011/01/05)
Compounds of formula (I): wherein: R1 represents a hydrogen atom or a group of formula COR4,or R1 represents a group of formula (A): R2 represents a group of formula NR5R6, or R2 represents a nitrogen-containing heterocyclic group, an aryl group or a heteroaryl group, R3 represents a hydrogen atom or an alkyl group, m represents an integer between 1 and 6 inclusive, n represents 0, 1 or 2, their optical isomers, and also addition salts thereof with a pharmaceutically acceptable acid. Medicinal products containing the same which are useful in treating and/or preventing thrombotic events.
Palladium-catalysed enantioselective α-hydroxylation of β-ketoesters
Smith, Alexander M.R.,Billen, Denis,Hii, King Kuok
supporting information; experimental part, p. 3925 - 3927 (2010/01/06)
Highly enantioselective α-hydroxylation of cyclic and acyclic 1,3-ketoesters can be achieved with up to 98% ee using a dicationic palladium(ii) catalyst and dimethyldioxirane as oxidant.
Azeotropic transesterification of β-keto esters
Christoffers, Jens,Oenal, Necla
, p. 1633 - 1635 (2007/10/03)
Transesterifications of methyl β-keto carboxylates catalyzed by DMAP with various high boiling alcohols can be accomplished in refluxing cyclohexane in a Dean-Stark trap. The MeOH formed is removed completely from the reaction mixture as an azeotrope lead
