- Ni-Catalyzed C(sp3)–O Arylation of α-Hydroxy Esters
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A Negishi cross-coupling of α-hydroxy ester derivatives and arylzinc reagents has been developed. This reaction tolerates both primary and secondary C(sp3)–O alcohol precursors and achieves efficient cross-coupling under Ni catalysis without the need for added external metal reductant, photocatalyst, or additives. The arylation of readily accessible C(sp3)–O electrophiles in this operationally simple, rapid, and mild reaction provides a complementary way of accessing desirable α-aryl ester products.
- Monteith, John J.,Rousseaux, Sophie A. L.
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p. 9485 - 9489
(2021/12/09)
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- AMIDE DERIVATIVES COMPRISING HETEROCYCLOALKYL RING
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PROBLEM TO BE SOLVED: To provide compounds or pharmacologically acceptable salts thereof that have excellent EP300 and/or CREBBP histone acetyltransferase inhibitory activity. SOLUTION: The invention provides compounds represented by the formula (1) in the figure or pharmacologically acceptable salts thereof. (In the formula (1), ring Q1, ring Q2, ring Q3, X and L are as defined in the specification.) SELECTED DRAWING: None COPYRIGHT: (C)2020,JPO&INPIT
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Paragraph 0278-0280
(2020/05/20)
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- Palladium-catalyzed carbonylation of benzylic ammonium salts to amides and esters: Via C-N bond activation
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An efficient palladium-catalyzed carbonylation reaction of readily available quaternary ammonium salts with CO is reported for the first time to afford arylacetamides and arylacetic acid esters via benzylic C-N bond cleavage. This protocol features mild reaction conditions under atmospheric pressure of CO, a redox-neutral process without an additional oxidant, and a broad substrate scope for various kinds of amines, alcohols and phenols.
- Yu, Weijie,Yang, Shuwu,Xiong, Fei,Fan, Tianxiang,Feng, Yan,Huang, Yuanyuan,Fu, Junkai,Wang, Tao
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supporting information
p. 3099 - 3103
(2018/05/22)
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- Direct, rapid and convenient synthesis of esters and thioesters using PPh3/N-chlorobenzotriazole system
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We have developed an efficient method for esterification and thioesterification of various carboxylic acids with different alcohols and thiols using PPh3/N-chlorobenzotriazole mixed reagent in CH2Cl2 at room temperature.
- Rouhi-Saadabad, Hamed,Akhlaghinia, Batool
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p. 253 - 263
(2014/02/14)
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- Catalysed asymmetric protonation of simple linear keto-enolic species a route to chiral α-arylpropionic acids
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The reaction cascade consisting of deprotection/decarboxylation/asymmetric protonation of enolic species, starting from open-chain benzyl β-oxo esters, has been studied. When carried out in the presence of catalytic amounts of cinchonine, the reaction gave optically active α-aryl ketones with up to 75% ee. Enantio-enriched (S)-3-phenyl-2-butanone can be converted into 2-phenylpropionic acid without racemisation. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Roy, Olivier,Riahi, Abdelkhalek,Henin, Francoise,Muzart, Jacques
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p. 3986 - 3994
(2007/10/03)
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- Asymmetric synthesis of (S)-β2-homoarylglycines
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The synthesis of racemic N-phthalyl β2-homoarylglycines 5 and their asymmetric transformation have been investigated. The key step is the stereoselective addition of the (R)-pantolactone to the corresponding prochiral ketene 7.
- Calmes, Monique,Escale, Francoise,Glot, Christele,Rolland, Marc,Martinez, Jean
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p. 2459 - 2466
(2007/10/03)
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- Benzyloxy(4-substituted benzyloxy)carbenes. Generation from oxadiazolines and fragmentation to radical pairs in solution
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Thermolysis of 2,2-dibenzyloxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline in benzene at 110°C leads to dibenzyloxycarbene. The carbene was trapped with tert-butyl alcohol to afford dibenzyl-tert-butyl orthoformate. In the absence of a trapping agent for the carbene, it fragmented to benzyloxycarbonyl and benzyl radicals, as shown by trapping the latter with TEMPO. In the absence of both TEMPO and tert-butyl alcohol, the radicals were partitioned between coupling to benzyl phenylacetate and decarboxylation, with subsequent formation of bibenzyl. The preferred sense of fragmentation of the analogous carbenes from benzyloxy-(p-substituted-benzyloxy)carbenes was determined by comparing the yields of the two possible esters, ArCH2O(CO)CH2Ph and PhCH2O(CO)CH2Ar. It was found that an electron-withdrawing group in the para position favoured fragmentation to the benzylic radical containing that group. A Hammett plot of the data gave a best fit with σ- substituent constants (r = 0.994, ρ((PhH, 110°C) = 0.7)) suggesting that the fragmentation involves charge separation in the sense that increases electron density on the group that is becoming a benzylic radical and decreases electron density on the carbonyl group that is becoming the benzyloxycarbonyl radical.
- Merkley,Warkentin
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p. 942 - 949
(2007/10/03)
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- Transesterification of methyl arylacetates wtih lithium alkoxides
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A series of methyl arylacetates were transesterified in excellent yields using lithium alkoxides derived from primary, secondary, and tertiary aliphatic alcohols, benzyl alcohols, and allyl alcohol.
- Bhawal,Khanapure,Biehl
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p. 112 - 114
(2007/10/02)
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- NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS, 8. TRIMETHYLSILYLDIAZOMETHANE, A NEW, STABLE, AND SAFE REAGENT FOR THE CLASSICAL ARNDT-EISTERT SYNTHESIS
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Stable and safe trimethylsilyldiazomethane (TMSCHN2) can be used efficiently for the Arndt-Eistert synthesis in place of highly toxic and explosive diazomethane.
- Aoyama, Toyohiko,Shioiri, Takayuki
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p. 4461 - 4462
(2007/10/02)
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- Photochemistry of α-Aryl Carboxylic Anhydrides. Part 4. Photoreactions of Some Asymmetrical Anhydrides derived from o- and p-Methoxyphenylacetic Acid, and of Some of the Phenylacetate Ester Photoproducts
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Irradiation of the two asymmetrical carboxylic anhydrides R1C6H4CH2.CO.O.CO.CH2C6H5 (1a and 1b) at 254 nm in acetonitrile leads to the formation of esters and bibenzyls.Among the esters produced, the asymmetrical ones with structure R1C6H4CH2.O(C=O)CH2C6H5 are the most abundant.These are for the greater part formed intramolecularly by decarbonylation of one excited anhydride molecule.This result is in line with a mechanism involving electron transfer after excitation of the anhydride molecule.The bibenzyls are formed by the recombination of benzyl radicals.In the initial stage of the reaction of the anhydrides, the three bibenzyls are formed with the asymmetrical one predominating .In the later stages, when substantial amounts of esters are present, the formation of the bibenzyls also originates in part from the photodecomposition of the esters.The photochemistry of the various (symmetrical and asymmetrical) esters which are photoproducts from the anhydrides (1a and b) has also been studied.The symmetrical esters (2a and b) afforded quantitatively the bibenzyls (3a and b), respectively.The asymmetrical esters gave variable yields of the three (possible) bibenzyls, depending on the type of ester considered.For the asymmetrical esters for which bibenzyl formation could be quenched by (Z)-piperylene, the three bibenzyls were formed in a close to statistical ratio, e.g. (2c) yielded the bibenzyls (3a, c, and e) in a ratio of 1:2.5:1.With the esters for which the photodecarboxylation was not quenchable by (Z)-piperylene, a relatively higher yield of the asymmetrical bibenzyl was found, e.g. (2d) yielded the bibenzyls (3b, d, and e) in a ratio of 1:6:1.These results are rationalized in terms of a recombination of free radicals resulting from the triplet excited esters after spin inversion in the former case, and a recombination of a radical pair in the solvent cage resulting from the singlet excited or shortlived triplet excited ester in the latter case.
- Roof, Antonius A. M.,Woerden, Hendrik F. van,Cerfontain, Hans
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p. 838 - 841
(2007/10/02)
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