- Ring size and nothing else matters: unusual regioselectivity of alkyne hydration by NHC gold(i) complexes
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We have investigated the role of ring sizes and substituents in NHC ligands in some (NHC)Au(i) complexes in the hydration of internal alkynes. Despite the fact that using (NHC)Au(i) complexes in the hydration of diarylacetylenes leads to Markovnikov-type products, the precise tuning of ligands allows changing the regioselectivity in arylalkylacetylene hydration to the anti-Markovnikov-type.
- Ageshina, Alexandra A.,Asachenko, Andrey F.,Chesnokov, Gleb A.,Minaeva, Lidiya I.,Nechaev, Mikhail S.,Philippova, Anna N.,Rzhevskiy, Sergey A.,Topchiy, Maxim A.
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supporting information
p. 5686 - 5689
(2021/06/16)
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- Synthesis of Diketones, Ketoesters, and Tetraketones by Electrochemical Oxidative Decarboxylation of Malonic Acid Derivatives: Application to the Synthesis of cis-Jasmone
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Disubstituted malonic acid derivatives are smoothly converted into diketones and ketoesters in good to excellent yield (68% to 91%) under electrochemical conditions. The scope can be extended to transform trisubstituted bis-malonic acids into tetraketones in 77% to 86% yield. The new method was applied to the total synthesis of cis-jasmone.
- Ma, Xiaofeng,Dewez, Damien F.,Du, Le,Luo, Xiya,Markó, István E.,Lam, Kevin
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- NOVEL VINYLBENZENE COMPOUND AND PHOTOSENSITIVE PHOTORESIST COMPOSITION COMPRISING THE SAME
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Provided is a photocurable composition comprising: (A) a photocurable compound; and (B) a vinylbenzene-containing monomer having a structure represented by chemical formula 1. In the chemical formula 1, X, R1, R2, R3, L, L1, L2 and L3 are the same as defi
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Paragraph 0133-0138
(2017/07/26)
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- Electrochemical Oxidative Decarboxylation of Malonic Acid Derivatives: A Method for the Synthesis of Ketals and Ketones
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A novel electrochemical oxidative decarboxylation of disubstituted malonic acids leading to dimethoxy ketals is described. In the presence of NH3, a wide range of disubstituted malonic acids was transformed into the corresponding ketals in good to excellent yields under electrochemical conditions. When the crude reaction mixture, obtained after electrolysis, was directly treated with 1 M aq HCl, the initially generated ketals were smoothly transformed into the corresponding ketones in a single vessel operation.
- Ma, Xiaofeng,Luo, Xiya,Dochain, Simon,Mathot, Charlotte,Markò, István E.
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p. 4690 - 4693
(2015/10/12)
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- Isolable gold(I) complexes having one low-coordinating ligand as catalysts for the selective hydration of substituted alkynes at room temperature without acidic promoters
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Hydration of a wide range of alkynes to the corresponding ketones has been afforded in high yields at room temperature by using gold(I)-phosphine complexes as catalyst, with no acidic cocatalysts required. Suitable substrates covering alkyl and aryl terminal alkynes, enynes, internal alkynes, and propargylic alcohols, including enantiopure forms, are cleanly transformed to the corresponding ketones in nearly quantitative yields. Acid-labile groups present in the substrates are preserved. The catalytic activity strongly depends on both the nature of the phosphine coordinated to the gold (I) center and the softness of the counteranion, the complex AuSPhOsNTf2 showing the better activity. A plausible mechanism for the hydration of alkynes through ketal intermediates is proposed on the basis of kinetic studies. The described catalytic system should provide an efficient alternative to mercury-based methodologies and be useful in synthetic programs.
- Leyva, Antonio,Corma, Avelino
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scheme or table
p. 2067 - 2074
(2009/08/07)
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- TiCl4-catalyzed indirect anti-Markovnikov hydration of alkynes: Application to the synthesis of benzo[b]furans
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(Chemical Equation Presented) An efficient methodology for the indirect anti-Markovnikov hydration of unsymmetrically substituted terminal and internal alkynes is based on TiCl4-catalyzed hydroamination reactions. Its application to ortho-alkynylhaloarenes, followed by a copper-catalyzed O-arylation, provides flexible access to substituted benzo[b]furans.
- Ackermann, Lutz,Kaspar, Ludwig T.
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p. 6149 - 6153
(2008/02/09)
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- Selective iron-catalyzed cross-coupling reactions of Grignard reagents with enol triflates, acid chlorides, and dichloroarenes
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Cheap, readily available, air stable, nontoxic, and environmentally benign iron salts such as Fe(acac)3 are excellent precatalysts for the cross-coupling of Grignard reagents with alkenyl triflates and acid chlorides. Moreover, it is shown that dichloroarene and -heteroarene derivatives as the substrates can be selectively monoalkylated by this method. All cross-coupling reactions proceed very rapidly under notably mild conditions and turned out to be compatible with a variety of functional groups in both reaction partners. A detailed analysis of the preparative results suggests that iron-catalyzed C-C bond formations can occur via different pathways. Thus, it is likely that reactions of methylmagnesium halides involve iron-ate complexes as the active components, whereas reactions of Grignard reagents with two or more carbon atoms are effected by highly reduced iron-clusters of the formal composition [Fe(MgX)2]n generated in situ. Control experiments using the ate-complex [Me4Fe]Li2 corroborate this interpretation.
- Scheiper, Bodo,Bonnekessel, Melanie,Krause, Helga,Fuerstner, Alois
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p. 3943 - 3949
(2007/10/03)
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- Reduction of Ketene Dithioacetal S,S-Dioxides with Sodium Borohydride and Its Application to a Convenient Synthesis of Alkyl Arylmethyl Ketones
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The C-C double bond of a ketene dithioacetal S,S-dioxide was found to undergo reduction with sodium borohydride.This fact provides an efficient synthetic route from an aromatic aldehyde to an alkyl arylmethyl ketone using methylthiomethyl p-totyl sulfone.
- Ogura, Katsuyuki,Ohtsuki, Kazuo,Takahashi, Kazumasa,Iida, Hirotada
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p. 1597 - 1598
(2007/10/02)
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- ALDEHYDE AND KETONE SYNTHESES USING METHYLTHIOMETHYL p-TOLYL SULFONE
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Methylthiomethyl p-tolyl sulfone (1) was conveniently alkylated to give mono- and dialkylated products (2 and 4).Reaction conditions for the transformation of 2 and 4 into aldehydes (3) and ketones (5), respectively, were exploited.
- Ogura, Katsuyuki,Ohtsuki, Kazuo,Nakamura, Masami,Yahata, Nobuhiro,Takahashi, Kazumasa,Iida, Hirotada
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p. 2455 - 2458
(2007/10/02)
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- α,β-Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. I. A Novel Synthesis of Dialkyl Ketones and a Synthesis of Aldehydes from Ketones by One Carbon Elongation
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Treatment of α,β-epoxy sulfoxides, prepared from 1-chloroalkyl phenyl sulfoxides with ketones or aldehydes, with sodium benzeneselenolate gives dialkyl ketones or aldehydes in good yields under mild conditions.The mechanism of this reaction and an application of this process to a formal total synthesis of dihydrojasmone are described.
- Satoh, Tsuyoshi,Kaneko, Youhei,Izawa, Takao,Sakata, Kiichi,Yamakawa, Koji
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p. 1983 - 1990
(2007/10/02)
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- A NOVEL SYNTHESIS OF DIALKYL KETONES AND α-SULFENYLATED CARBONYL COMPOUNDS FROM α,β-EPOXY SULFOXIDES
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Treatment of α,β-epoxy sulfoides with excess sodium phenylselenide and various kinds of alkylthiolates gave dialkyl ketones and α-sulfenylated carbonyl compounds, respectively, in good yields under mild conditions.
- Satoh, Tsuyoshi,Kaneko, Youhei,Kumagawa, Takumi,Izawa, Takao,Sakata, Kiichi,Yamakawa, Koji
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p. 1957 - 1960
(2007/10/02)
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- Transformation of Alkyl Halides to Aldehydes Having Two Additional Carbon Atoms
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Methyl 3-oxo-4-phenylbutanoate (6) reacts with alkyl halides (1a-g) in the presence of NaH/benzene to furnish alkylated β-keto esters (2a-g).Hydrolysis of 2a-g gives benzyl ketones (3a-g), which on reduction with sodium borohydride give the homobenzylic alcohols (4a-g).The alcohols (4a-g) are readily fragmented to aldehydes (5a-g) on heating with lead tetraacetate/iodine.
- Shankaran, K.,Talekar, D. G.,Rao, A. S.
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p. 408 - 410
(2007/10/02)
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