19980-19-9Relevant academic research and scientific papers
Easy preparation of enoxysilanes from aldehydes and ketones catalyzed by samarium diiodide
Hydrio, Jerome,Van De Weghe, Pierre,Collin, Jacqueline
, p. 68 - 72 (1997)
Ketones and α-substituted aldehydes are converted to trimethylsilyl enol ethers by reaction with the trimethylsilyl ketene acetal of methyl isobutyrate in dichloromethane in presence of a catalytic amount of samarium diiodide.
Photocontrolled Cobalt Catalysis for Selective Hydroboration of α,β-Unsaturated Ketones
Beltran, Frédéric,Bergamaschi, Enrico,Funes-Ardoiz, Ignacio,Teskey, Christopher J.
supporting information, p. 21176 - 21182 (2020/09/17)
Selectivity between 1,2 and 1,4 addition of a nucleophile to an α,β-unsaturated carbonyl compound has classically been modified by the addition of stoichiometric additives to the substrate or reagent to increase their “hard” or “soft” character. Here, we demonstrate a conceptually distinct approach that instead relies on controlling the coordination sphere of a catalyst with visible light. In this way, we bias the reaction down two divergent pathways, giving contrasting products in the catalytic hydroboration of α,β-unsaturated ketones. This includes direct access to previously elusive cyclic enolborates, via 1,4-selective hydroboration, providing a straightforward and stereoselective route to rare syn-aldol products in one-pot. DFT calculations and mechanistic experiments confirm two different mechanisms are operative, underpinning this unusual photocontrolled selectivity switch.
Halogenative difluorohomologation of ketones
Fedorov, Oleg V.,Kosobokov, Mikhail D.,Levin, Vitalij V.,Struchkova, Marina I.,Dilman, Alexander D.
, p. 5870 - 5876 (2015/06/16)
A method for the difluorohomologation of ketones accompanied by halogenation of a C-H bond is described. The reaction involves silylation, difluorocarbene addition using Me3SiCF2Br activated by a bromide ion, and halogenation of intermediate cyclopropanes with N-bromo- or N-iodosuccinimide. The whole process is performed without isolation of intermediates. The resulting α,α-difluoro-β-halo-substituted ketones can be readily converted into fluorine containing pyrazole derivatives and oxetanes.
Enantioselective desymmetrization of prochiral ketones via an organocatalytic deprotonation process
Claraz, Aurelie,Oudeyer, Sylvain,Levacher, Vincent
, p. 764 - 768 (2013/07/25)
The first desymmetrization of 4-substituted cyclohexanones by organocatalytic asymmetric deprotonation at low catalyst loading is reported. The combination of N,O-bis(trimethylsilyl)acetamide (BSA) and chiral quaternary ammonium aryloxide salts has been u
METHOD FOR PRODUCING SILYLENOL ETHERS
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Paragraph 0095-0096, (2013/03/26)
The present invention provides a method for producing a silyl enol ether compound, which is convenient, has highly broad utility and places a low environmental load (less waste). The present invention relates to a method for producing silyl enol ether compound (3), including reacting ketone or aldehyde compound (1) with allylsilane compound (2) in the presence of a base and 0.00001 to 0.5 equivalents of an acid catalyst relative to ketone or aldehyde compound (1), wherein R1 is a hydrogen atom, an alkyl group, an aryl group or the like; R2 and R3 are each a hydrogen atom, a halogen atom, an alkyl group, an aryl group or the like; R1 and R3, R1 and R2, or R2 and R3 optionally form a ring, together with the carbon atom(s) bonded thereto; R4 , R5 and R6 are each a hydrogen atom, an alkyl group or the like; two of R4, R5 and R6 optionally form a ring; R7, R8, R9, R10 and R11 are each a hydrogen atom, an alkyl group or the like; two of R7, R8, R9, R10 and R11 optionally form a ring.
Preparation of silyl enol ethers using (bistrimethylsilyl)acetamide in ionic liquids
Smietana, Michael,Mioskowski, Charles
, p. 1037 - 1039 (2007/10/03)
(matrix presented) Ionic liquids have been used for the preparation of silyl enol ethers from aldehydes and ketones with (bistrimethylsilyl)acetamide (BSA) in good yields.
New synthesis and reactions of [Sm(OTf)2(DME)2], a salt-free samarium(II) triflate
Collin, Jacqueline,Giuseppone, Nicolas,Machrouhi, Fouzia,Namy, Jean-Louis,Nief, Francois
, p. 3161 - 3164 (2007/10/03)
A new, simple and high-yield synthesis of a salt-free samarium(II) triflate, [Sm(OTf)2(DME)2] is described. In stoichiometric amounts this derivative mediates typical samarium (II) coupling reactions such as pinacolisation, dimerisat
Alkyl Migration in Competition with Phenylthio Migration in the Acid-catalysed Rearrangement of Alcohols
Hannaby, Malcolm,Warren, Stuart
, p. 3007 - 3014 (2007/10/02)
Sulfonate derivatives of conformationally rigid syn-2-phenylthiocyclohexanols, which are prevented from phenylthio migration by stereochemistry, rearrange slowly by alkyl migration or ring contraction.In contrast to other electronegative groups, phenylthio slows the reaction down but allows migration of other groups.
THE 1,3 OC SILYL REARRANGEMENT OF SILYL ENOL ETHER ANIONS - SYNTHESIS OF α-SILYL KETONES
Corey, E. J.,Ruecker, Christoph
, p. 4345 - 4348 (2007/10/02)
Silyl enol ethers with sterically hindered silyl groups are transformed into the corresponding α-silyl ketones by treatment with n-butyllithium/potassium tert-butylate.
