- Rapid, One-Step Synthesis of α-Ketoacetals via Electrophilic Etherification
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Herein, we report a rapid, one-step synthesis of α-ketoacetals via electrophilic etherification of α-alkoxy enolates and monoperoxyacetals. Methyl, primary, and secondary α-ketoacetals were obtained in 44-63% yields from tetrahydropyranyl substrates; usin
- Paris, Timothy J.,Schwartz, Chris,Sundall, Eric,Willand-Charnley, Rachel
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p. 14797 - 14811
(2021/10/20)
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- New platinum-catalysed dihydroalkoxylation of allenes
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A new platinum-catalysed dihydroalkoxylation of alienes is described to give aliphatic acetals by an unexpected attack of two molecules of methanol to the terminal carbon of the aliene moiety. Deuteration experiments suggest an unprecedented formal 1,3-dipolar addition of methanol to a zwitterionic platinum carbene as the key step. The first platinum-catalysed intermolecular carbonbased nucleophile addition to alienes is also reported.
- Munoz, Maria Paz,De La Torre, Maria C.,Sierra, Miguel A.
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supporting information; experimental part
p. 2189 - 2194
(2010/11/04)
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- Solvent directed electrophilic iodination and phenylselenenylation of activated alkyl aryl ketones
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A mixture of molecular iodine and phenyliodine(III) bis(trifluoroacetate) (BTI) in CH3CN (or CH3OH) iodinates the aromatic ring of some activated alkyl aryl ketones. A different outcome results if PhSeSePh is used instead of I2
- Panunzi, Barbara,Rotiroti, Lucia,Tingoli, Marco
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p. 8753 - 8756
(2007/10/03)
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- Substituted benzyl oximino compounds
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The present invention relates to benzyloxyimino compounds of the formula I, where: R1to R4, X, Y, and Z are as defined in the specification.
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- Regiospecific synthesis of α-diones, α,α-dialkoxyketones and α-alkoxy-α-sulfenylated ketones
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A convenient synthesis of α-diones and their monoprotected acetals, i.e. α-ketoacetals, was developed by mercury induced solvolysis of regiospecifically formed α-chloro-α-(alkylthio)ketones. Analogously, α-alkoxy-α-sulfenylated ketones were formed when reacting α-chloro-α-sulfenylated ketones with an alkaline alcoholic medium, α-Alkoxy-α-sulfenylated ketones themselves could be transformed into α-diones or ?-ketoacetals, which in turn were hydrolyzed under anhydrous conditions into the corresponding α-diones. (C) 2000 Elsevier Science Ltd.
- Tehrani,Boeykens,Tyvorskii,Kulinkovich,De Kimpe
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p. 6541 - 6548
(2007/10/03)
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- Liquid photoinitiator mixtures
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Liquid highly active photoinitiators are obtained by dissolving a solid photoinitiator of the titanocene type in liquid photoinitiators of the acetal or ketal type. The liquid mixtures have a long dark storage stability.
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- Oxygen-containing titanocenes, and the use thereof
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Titanocenes of the formula I STR1 in which R1 are cyclopentadienyl? groups and R2 and R3 are aromatic radicals which are substituted in both ortho-positions by fluorine and, in addition, are substituted by an acyloxy group are suitable as photoinitiators for the photopolymerization of ethylenically unsaturated compounds.
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- Titanocenes, the use thereof, and n-substituted fluoroanilines
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Titanocenes containing two 5-membered cyclodienyl gropus, for example cyclopentadienyl, and one or two 6-membered carbocyclic or 5- or 6-membered heterocyclic aromatic rings which are substituted by a fluorine atom in at least one of the two ortho-positions to the titanium-carbon bond and contain, as further substituents, a substituted amino radical, are suitable as photoinitiators for radiation-induced polymerization of ethylenically unsaturated compounds.
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- Titanocenes, the use thereof, and N-substituted pyrroles
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Titanocenes containing two 5-membered cyclodienyl groups, for example cyclopentadienyl, and one or two 6-membered carbocyclic or 5- or 6-membered heterocyclic aromatic rings which are substituted by a fluorine atom in at least one of the two ortho-positions to the titanium-carbon bond and contain, as a further substituent, unsubstituted or substituted 1-pyrryl, are suitable as photoinitiators for radiation-induced polymerization of ethylenically unsaturated compounds.
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- Novel nitrogen-containing titanocenes, and the use thereof
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Titanocenes of the formula I STR1 in which R1 are cyclopentadienyl? groups and R2 and R3 are aromatic radicals which are substituted in both ortho-positions by fluorine and, in addition, are substituted by a pyrrylalkyl group, amidoalkyl group or imidoalkyl group, are suitable as photoinitiators for the photopolymerization of ethylenically unsaturated compounds.
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- REACTIONS OF 1-ARYL-2,2-DICHLORO-1-PROPANONES. II. REACTION OF 1-(4-R-PHENYL)-2,2-DICHLORO-1-PROPANONES WITH SOME NUCLEOPHILES
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The reactions of 1-(4-R-phenyl)-2,2-dichloro-1-propanones with alkali-metal alkoxides and certain amines (morpholine, piperidine) and also their conversion into α-diketones were studied.By IR and mass spectrometry it was shown that the methoxylation of these compounds with sodium methoxide leads to the formation of the products from direct substitution of the halogen atoms by methoxyl groups.The kinetics of methoxylation are described by a second-order equation, and a Hammett correlation with a positive reaction constant is observed in the rate constants.
- Bratchanskii, P. E.,Komissarova, G. G.,Esipov, G. V.
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p. 1961 - 1964
(2007/10/02)
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- Rearrangement of 1-Aryl-2,2-dihalo-1-alkanones
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Reaction of 1-aryl-2,2-dichloro-1-alkanones with alkoxides in the corresponding alcohol afforded a mixture of 1-aryl-2,2-dialkoxy-1-alkanones and 1-aryl-1,1-dialkoxy-2-alkanones.The mechanism was shown to proceed via α-chloro-α'-alkoxy epoxides, which rearranged into 1-alkoxy-1-aryl-1-chloro-2-alkanones, the latter giving the final compounds via either another epoxide intermediate or a solvolysis mechanism. α,α-Dibromo- and α-bromo-α-chloroalkyl aryl ketones behaved analogously, but α-bromo-α-fluoro- and α-chloro-α-fluoroalkyl aryl ketones gave exclusively solvolysis of initially formed 1-alkoxy-1-aryl-1-fluoro-2-alkanones, resulting in rearranged 1-aryl-1,1-dialkoxy-2-alkanones. α,α-Difluoroalkyl aryl ketones did not rearrange but underwent reduction of the carbonyl function on treatment with sodium methoxide in methanol.The influence of varying factors, such as the steric requirements of the alkoxide and the substrate, the concentration of the alkoxide, the aromatic substituent, the temperature, and the halogens, was investigated and correlated to the mechanism involved.
- Kimpe, Norbert De,Verhe, Roland,Buyck, Laurent De,Schamp, Niceas
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p. 2803 - 2813
(2007/10/02)
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