- Carboxylation of Alkenyl Boronic Acids and Alkenyl Boronic Acid Pinacol Esters with CO2 Catalyzed by Cuprous Halide
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A cuprous halide catalysed carboxylation of alkenyl boronic acids and alkenyl boronic acid pinacol esters under CO2, affording the corresponding α, β-unsaturated carboxylic acids in good yield, has been developed. The potassium (E)-trifluoro(styryl)borate is also compatible with this reaction. This simple and efficient copper(I) catalytic system showed good functional group tolerance.
- Hong, Junting,Nayal, Onkar S.,Mo, Fanyang
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supporting information
p. 2813 - 2818
(2020/05/16)
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- Method for preparing alpha, beta-unsaturated carboxylic acid by reacting alkenyl boron compound with carbon dioxide under catalysis of cuprous halide
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The invention discloses a method for preparing alpha, beta-unsaturated carboxylic acid through a carboxylation reaction of an alkenyl boron compound and carbon dioxide under the catalysis of cuprous halide. According to the method, carbon dioxide is used as a C1 source, the cuprous halide is adopted for catalysis, and alkoxide serves as alkali to react in an organic solvent, so the method is simple and easy to implement, has a wide substrate application range, converts various alkenyl boron compounds such as alkenyl boric acid, alkenyl borate and borate into corresponding alpha, beta-unsaturated carboxylic acid under mild conditions, and has a very high yield. The obtained product alpha, beta-unsaturated carboxylic acid is an important intermediate for preparing fine chemical products suchas perfumes, insecticides and the like.
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Paragraph 0091-0092
(2020/06/17)
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- Cu/Fe-Cocatalyzed Formation of β-Ketophosphonates by a Domino Knoevenagel-Decarboxylation-Oxyphosphorylation Sequence from Aromatic Aldehydes and H-Phosphonates
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A domino Knoevenagel-decarboxylation-alkene difunctionalization sequence has been developed for the conversion of benzaldehydes into β-ketophosphonates, catalyzed by a cooperative Cu/Fe system, whereby CP and CO bonds are formed simultaneously in a one-pot reaction. The reaction proceeds in good yields and with a broad substrate scope and environmentally benign conditions.
- Zhou, Mingxin,Zhou, Yao,Song, Qiuling
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supporting information
p. 10654 - 10658
(2015/07/20)
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- Improved synthesis of natural ester sintenin and its analogues via Wittig reaction
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The synthesis of a cytotoxic natural ester sintenin (7a) and twenty eight of its analogues including nitrogen-containing heterocyclic indole moiety (7b-7t), saturated (10a-10d) and unsaturated (10e-10h) amides were carried out by convenient route via one-pot Wittig reaction in aqueous medium with improved yield. A systematic structure activity relationship of sintenin ester was designed by chemically modified derivatives in order to get better cytotoxicity.
- Sharma, Mukul,Rajesh, U. Chinna,Rawat, Diwan S.
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p. 1853 - 1860
(2014/01/17)
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- Synthesis and anticancer activity of 13-membered cyclic enediynes
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We herein describe the synthesis of 15 novel 13-membered cyclic enediyne derivatives using simple and straightforward approach. Representative examples were screened for their anticancer activities on 60 different human tumor cell lines representing various histologies viz. leukemia, melanoma, and cancers of lung, colon, kidney, ovary, breast, prostate, and central nervous system. The enediyne derivatives with halogen substitutions, especially fluorides were found to be active against most of the cell lines. The initial results indicates marginal to good inhibition for the growth of tumor cells for several cell lines, which shows the potential of these class of compound towards anticancer application. 15 novel 13-membered cyclic enediyne derivatives using a simple and straightforward approach are synthesized. The initial results show the potential of this class of compounds towards anticancer application. Copyright
- Sharma, Mukul,Joshi, Mukesh C,Kumar, Vineet,Malhotra, Sanjay V.,Rawat, Diwan S.
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scheme or table
p. 567 - 571
(2012/06/30)
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- Phenylalanine aminomutase-catalyzed addition of ammonia to substituted cinnamic acids: A route to enantiopure α- and β-amino acids
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(Chemical Equation Presented) An approach is described for the synthesis of aromatic α- and β-amino acids that uses phenylalanine aminomutase to catalyze a highly enantioselective addition of ammonia to substituted cinnamic acids. The reaction has a broad scope and yields substituted α- and β-phenylalanines with excellent enantiomeric excess. The regioselectivity of the conversion is determined by substituents present at the aromatic ring. A box model for the enzyme active site is proposed, derived from the influence of the hydrophobicity of substituents on the enzyme affinity toward various substrates.
- Szymanski, Wiktor,Wu, Bian,Weiner, Barbara,De Wildeman, Stefaan,Feringa, Ben L.,Janssen, Dick B.
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supporting information; experimental part
p. 9152 - 9157
(2010/03/01)
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- Structure-activity relationships of phenylpropanoids as antifeedants for the pine weevil Hylobius abietis
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Ethyl cinnamate has been isolated from the bark of Pinus contorta in the search for antifeedants for the pine weevil, Hylobius abietis. Based on this lead compound, a number of structurally related compounds were synthesized and tested. The usability of the Topliss scheme, a flow diagram previously used in numerous structure-activity relationship (SAR) studies, was evaluated in an attempt to find the most potent antifeedants. The scheme was initially followed stepwise; subsequently, all compounds found in the scheme were compared. In total, 51 phenylpropanoids were tested and analyzed for SARs by using arguments from the field of medicinal chemistry (rational drug design). Individual Hansch parameters based on hydrophobicity, steric, and electronic properties were examined. The effects of position and numbers of substituents on the aromatic ring, the effects of conjugation in the molecules, and the effects of the properties of the parent alcohol part of the esters were also evaluated. It proved difficult to find strong SARs derived from single physicochemical descriptors, but our study led to numerous new, potent, phenylpropanoid antifeedants for the pine weevil. Among the most potent were methyl 3-phenylpropanoates monosubstituted with chloro, fluoro, or methyl groups and the 3,4-dichlorinated methyl 3-phenylpropanoate.
- Bohman,Nordlander,Nordenhem,Sunnerheim,Borg-Karlson,Unelius
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p. 339 - 352
(2008/09/18)
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- Mass spectrometric screening of enantioselective Diels-Alder reactions
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(Chemical Equation Presented) A rapid cat. scan: Mass spectrometric monitoring of reaction intermediates of the retro-Diels-Alder reaction has allowed the rapid screening of catalysts for enantioselective Diels-Alder reactions (see scheme). Copper catalysts as well as metal-free organocatalysts were tested. A protocol for the simultaneous screening of catalyst mixtures has also been developed, which offers new possibilities for high-throughput catalyst development.
- Teichert, Antje,Pfaltz, Andreas
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experimental part
p. 3360 - 3362
(2009/02/07)
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- Discovery of potent, orally available vanilloid receptor-1 antagonists. Structure-activity relationship of N-aryl cinnamides
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The vanilloid receptor-1 (TRPV1 or VR1) is a member of the transient receptor potential (TRP) family of ion channels and plays a role in regulating the function of sensory nerves. A growing body of evidence demonstrates the therapeutic potential of TRPV1 modulators, particularly in the management of pain. As a result of our screening efforts, we identified (E)-3-(4-tert- butylphenyl)-N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)acrylamide (1), an antagonist that blocks the capsaicin-induced and pH-induced uptake of 45Ca2+ in TRPV1-expressing Chinese hamster ovary cells with IC50 values of 17 ± 5 and 150 ± 80 nM, respectively. In this report, we describe the synthesis and structure-activity relationship of a series of N-aryl cinnamides, the most potent of which (49a and 49b) exhibit good oral bioavailability in rats (Foral = 39% and 17%, respectively).
- Doherty, Elizabeth M.,Fotsch, Christopher,Bo, Yunxin,Chakrabarti, Partha P.,Chen, Ning,Gavva, Narender,Han, Nianhe,Kelly, Michael G.,Kincaid, John,Klionsky, Lana,Liu, Qingyian,Ognyanov, Vassil I.,Tamir, Rami,Wang, Xianghong,Zhu, Jiawang,Norman, Mark H.,Treanor, James J. S.
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- Novel titanium(IV) chloride catalyzed olefination of aldehydes: A simple and convenient synthesis of trans-cinnamic acids
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A variety of aromatic aldehydes were stereoselectively transformed into (E)-cinnamic acids via the reaction with ethyl bromoacetate and triphenylphosphine in the presence of catalytic amount of titanium tetrachloride, followed by hydrolysis and crystallization.
- Basavaiah, Deevi,Jaganmohan Rao, Anumolu
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p. 195 - 201
(2007/10/03)
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