- 4-Phenyl quinoline derivatives as potential serotonin receptor ligands with antiproliferative activity
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Antagonists of signaling receptors are often effective non-toxic therapeutic agents. Over the years, there have been evidences describing the role of serotonin or 5-hydroxytryptamine (5-HT) in development of cancer. Although there are reports on the antip
- Joshi, Pranaya V.,Sayed, Alim A.,RaviKumar, Ameeta,Puranik, Vedavati G.,Zinjarde, Smita S.
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p. 246 - 258
(2017/05/12)
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- Thioamide-Directed Cobalt(III)-Catalyzed Selective Amidation of C(sp3)?H Bonds
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A mild, oxidant-free, and selective Cp*CoIII-catalyzed amidation of thioamides with robust dioxazolone amidating agents via C(sp3)?H bond activation to generate the desired amidated products is reported. The method is efficient and allows for the C?H amidation of a wide range of functionalized thioamides with aryl-, heteroaryl-, and alkyl-substituted dioxazolones under the Cp*CoIII-catalyzed conditions. The observed regioselectivity towards primary C(sp3)?H activation is supported by computational studies and the cyclometalation is proposed to proceed by means of an external carboxylate-assisted concerted metalation/deprotonation mechanism. The reported method is a rare example of the use of a directing group other than the commonly used pyridine and quinolone classes for Cp*CoIII-catalyzed C(sp3)?H functionalization and the first to exploit thioamides.
- Tan, Peng Wen,Mak, Adrian M.,Sullivan, Michael B.,Dixon, Darren J.,Seayad, Jayasree
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supporting information
p. 16550 - 16554
(2017/12/07)
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- Bromination of enamines from tertiary amides using the petasis reagent: A convenient one-pot regioselective route to bromomethyl ketones
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An original one-pot synthesis of bromomethyl ketones is achived using the Petasis reagent (dimethyltitanocene) as a key for enamine generation. Several amides were used to test the limits of the procedure by changing either the alkyl chain R or the amino portion of the starting materials. The enamines generated in situ were allowed to react with bromine at low temperature followed by hydrolysis to yield bromomethyl ketones in excellent yields (85 to 95%). Mechanistic details and optimum conditions for the reaction are briefly discussed. The present approach offers several advantages such as regioselectivity in enamine formation, good yields, mild reaction conditions, and ease of experimentation.
- Kobeissi, Marwan,Cherry, Khalil,Jomaa, Wissam
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supporting information
p. 2955 - 2965
(2013/09/02)
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- Selective catalytic sp3 C-O bond cleavage with C-N bond formation in 3-alkoxy-1-propanols
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The ruthenium catalyzed selective sp3 C-O cleavage with amide formation was reported in reactions of 3-alkoxy-1-propanol derivatives and amines. The cleavage only occurs at the C3-O position even with 3-benzyloxy-1-propanol. Based on the experimental results, O-bound and C-bound Ru enolate complexes were proposed as key intermediates for the unique selective sp3 C-O bond cleavage in 3-alkoxy-1-propanols.
- Chen, Cheng,Hong, Soon Hyeok
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supporting information; experimental part
p. 2992 - 2995
(2012/07/28)
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- New, efficient, selective, and one-pot method for acylation of amines
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Hydrazine hydrate with acetic and propionic acids was an efficient reagent for acylation of primary and secondary amines at reflux temperatures. The reported one-pot method is high-yielding, simple, mild, and inexpensive. Copyright Taylor & Francis Group, LLC.
- Basanagouda, Mahantesha,Kulkarni, Manohar V.,Kalkhambkar, Raj G.,Kulkarni, Geeta M.
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p. 2929 - 2940
(2008/12/22)
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- Efficient procedure for the preparation of amides using polymer-bound reagents
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An effective method for the conversion of acids into amides is presented. The two-step procedure includes the preparation of acid chloride intermediates using Pol-Ph3P and subsequent treatment of these intermediates with amines and polymer-bound base. The amides were accessible in high yields and purities without further purification.
- Buchstaller,Ebert,Anlauf
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p. 1001 - 1005
(2007/10/03)
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- Enolboration. 7. Dicyclohexyliodoborane, a Highly Stereoselective Reagent for the Enolboration of Tertiary Amides. Effects of Solvent and Aldolization Temperature on Stereochemistry in Achieving the Stereoselective Synthesis of either Syn or Anti Aldols
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A highly stereoselective enolboration of tertiary amides has been accomplished for the first time with dicyclohexyliodoborane, Chx2BI.A systematic study of the enolboration of representative N,N-dialkylpropionamides (CH3CH2CONR'2) with Chx2BI in the presence of various tertiary amines of variable steric requirements revealed an unusual aldol stereoselectivity in different solvents and at different aldolization temperatures.Both the nature of solvent and the aldolization temperature influence the stereochemistry of enolboration, with the solvent effect being greater than that of the temperature.Aliphatic and alicyclic hydrocarbon solvents favor formation of the syn aldols from the enol borinates by aldolization at lower temperature (-78 deg C), whereas most of the other solvents examined, such as aromatic and chlorinated aliphatic solvents, favor formation of the anti aldols by aldolization at relatively higher temperatures (0 or 25 deg C).The remarkable effects of both temperature and solvent in the case of tertiary amides raise a question about the validity of the previously assumed constancy of the Z to syn and E to anti relationship, suggesting either a possible isomerization of enol borinates with temperature or a different aldolization transition state with different solvent.While the effect of stric requirements of the dialkylamino group of the tertiary amide does not contribute significantly to the stereochemistry, that of the amine exerts a considerable influence.The present study establishes a simple procedure for the stereoselective synthesis of either syn or anti aldols from representative tertiary amides merely by changing the solvent and the aldolization temperature.
- Ganesan, Kumaraperumal,Brown, Herbert C.
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p. 7346 - 7352
(2007/10/02)
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- Preparation and Characterization of 1,5-Diacyl-2,4-dioxohexahydro-1,3,5-triazines with Higher Acyl Groups
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The title compounds were prepared from 2,4-dioxohexahydro-triazine (DHT) and the corresponding acid chlorides in the presence of sulphuric acid.They are active acylating agents against piperidine in dioxane as the solvent.Only the diacyl derivatives of DHT with acyl chain lengths up to C6 react with aqueous solutions of sodium perborate forming the corresponding peroxy acids.
- Hofmann, Joerg,Just, Gerhard,Pritzkow, Wilhelm
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- Stereochemistry of the Michael Addition of N,N-Disubstituted Amide and Thioamide Enolates to α,β-Unsaturated Ketones
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A systematic study of the regio- and diastereoselectivity of the kinetic Michael addition of amide and thioamide enolates to a series of α,β-unsaturated ketones has been carried out.Factors that influence the diastereo- and regiochemical outcome of the reaction include the substitution pattern of the enone and enolate, the enolate counterion, and the solvent.Numerous examples of high selectivity have been discovered.In a number of examples, either the syn or the anti addition products can be obtained by varying the nature of the solvent, donor atom, and/or counterion.These results have correlated in terms of a coherent transition-state model.
- Oare, David A.,Henderson, Mark A.,Sanner, Mark A.,Heathcock, Clayton H.
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p. 132 - 157
(2007/10/02)
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- Studies on the Oxidation of Enamines with Molecular Oxygen. I. Oxidation of Some Piperidino Alkenes
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In the autoxidation of 1-piperidinocyclohex-1-ene (1), 1-piperidinobut-1-ene (2), 3-piperidinopent-2-ene (3), and 1-piperidino-2-methyl-prop-1-ene (4) only products of an oxidative attack at the C=C-double bond are formed.Both α-aminoketones, the products of the rearrangement of primarily formed epoxides, and products of the oxidative scission of the C=C double bond are obtained.As a side reaction some hydrolysis of the starting enamines takes place.This hydrolysis proves that some water must be formed during the enamine oxidation.
- Blau, Karla,Voerckel, V.
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p. 285 - 292
(2007/10/02)
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- A Synthesis of α-Substituted Amines
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The reaction of amides with organolithium reagents followed by hydride reducing agents has been studied as a synthetic route to α-substituted amines.The stereochemistry of the amine has been observed to depend upon the nature of the reducing agent.
- Hwang, Yuing C.,Chu, Min,Fowler, Frank W.
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p. 3885 - 3890
(2007/10/02)
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- Investigation of New Chiral 1,3-Oxazolidine-2-thiones: Analytical Separation and Optical Resolution of Racemic Carboxylic Acids and Amino Acids
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New chiral five-memebered heterocycles, (4S)-(4) and (4R)-4-ethyl-1,3-oxazolidine-2-thione (5), (4S)-4-isopropyl-1,3-oxazolidine-2-thione (6), and (4R,5S)-4-methyl-5-phenyl-1,3-oxazolidine-2-thione (7) have been developed.Among these heterocycles, (4R,5S)-MPOT (7) proved to be an excellent chiral reagent for analytical and efficient separation of racemic products from transformations of chiral carboxylic acids and amino acids.
- Nagao, Yoshimitsu,Kumagai, Toshio,Yamada, Shozo,Fujita, Eiichi,Inoue, Yoshinori,et al.
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p. 2361 - 2368
(2007/10/02)
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