- η2-dba complexes of Pd(0): The substituent effect in Suzuki-Miyaura coupling
-
(Chemical equation presented) The influence of aryl substituents in dibenzylidene acetone (dba) ligands, for Pd(0) complexes, has been evaluated for Suzuki-Miyaura cross-coupling reactions. Electron-withdrawing substituents such as NO2 or CF3 deactivate the catalyst species whereas strongly donating substituents such as OMe increase catalytic activity over that of unsubstituted dba ligands.
- Fairlamb, Ian J. S.,Kapdi, Anant R.,Lee, Adam F.
-
-
Read Online
- Silica gel-mediated self-aldol reactions of highly volatile aldehydes under organic solvent-free conditions without reflux condenser
-
Silica gel-mediated self-aldol reactions were catalyzed by piperidine to give the corresponding α,β-conjugated aldehydes in good yields. The aldol reactions of 4-nitro-, 4-trifluoromethyl-, and 4-chlorobenzaldehydes with acetone afforded the corresponding aldol products. Highly volatile aldehydes and acetone could be employed even without a reflux condenser for these reactions. Silica gel could be recycled five times without any significant decrease of the yields of the products.
- Tanemura, Kiyoshi
-
p. 1924 - 1928
(2019/06/24)
-
- A process for synthesizing [...] (by machine translation)
-
The present invention provides a process for synthesizing [...], including 2-hydrazino -5,5-dimethyl -1, 4, 5, 6-Tetrahydropyrimidines, their production and use hydrochloric acid salt and 1,5-bis-(4-trifluoromethyl phenyl) - 1,4-pentadiene-3-ketone preparation, and the raw material to the two, to isopropanol or ethanol as the solvent, the role of the concentrated hydrochloric acid produces [...]. By changing the synthesis process of the present invention, the reaction efficiency is improved. 2-hydrazino -5,5-dimethyl -1, 4, 5, 6-Tetrahydropyrimidines, their production and use the yield of the hydrochloride salt from 78% to 90% or more. 1,5-double (4-trifluoromethyl phenyl) - 1,4-pentadiene-3-one of the from the literature reports the yield of 83% to 90% or more. (by machine translation)
- -
-
Paragraph 0047; 0048; 0049; 0050
(2016/10/10)
-
- Tandem hydrogenation and condensation of fluorinated α,β-unsaturated ketones with primary amines, catalyzed by nickel
-
A simple homogeneous catalytic system based on nickel phosphine complexes has been developed for the transfer hydrogenation and condensation of α,β-unsaturated ketones to yield saturated ones and saturated imines using primary amines as hydrogen donors. Thus, a wide range of fluorinated 1,5-diaryl-1,4-pentadiene-3-ones were allowed to react with substituted benzylamines in the presence of [(dippe)Ni(μ-H)]2 (dippe = 1,2-bis-(diisopropylphosphino)-ethane) using ethanol as a solvent at 180 °C to give the corresponding saturated carbonyl compounds; here hydrogenation of the CC bond was preferred over the CO bond. Under the same reaction conditions but using an excess of benzylamine, a tandem process is then favoured, starting also with the reduction of the CC bond followed by a nucleophilic addition of the primary amine to yield valuable saturated imines with good to excellent yields (62%-91%).
- Castellanos-Blanco, Nahury,Flores-Alamo, Marcos,García, Juventino J.
-
supporting information
p. 15653 - 15663
(2015/09/07)
-
- COMPOUNDS USEFUL AGAINST KINETOPLASTIDEAE PARASITES
-
Dibenzylidene and heterobenzylideneacetone derivatives, related 4-piperidones, related 4-thiopyranones and the corresponding sulfinyl- and sulfonyl-analogues for their use for prophylaxis or treatment of trypanosomiasis and leishmaniasis.
- -
-
Page/Page column 16
(2012/09/05)
-
- Lewis acid mediated diastereoselective synthesis of fused fluorinated spiroketal as potential biologically active compounds
-
A series of substituted dibenzalacetones prepared using standard procedures were condensed with 5-methyl, 5-phenyl, and 5-trifluoromethyl-1,3- cyclohexanediones respectively, in toluene containing BF3·OEt as the Lewis acid catalyst. The reaction was found to be highly diastereoselective (dr, 9:1). The resulting spiroketals 1a-r were formed in moderate to good yields. In addition, a synthetically and biologically useful by-product identified as chromenone 7 was observed.
- Agbaje, Oluropo C.,Fadeyi, Olugbeminiyi O.,Okoro, Cosmas O.
-
scheme or table
p. 5297 - 5300
(2011/10/30)
-
- Activation of NFκB is inhibited by curcumin and related enones
-
The transcription factor NFkappaB (NFκB) is up-regulated in many cancer cells where it contributes to development of the pro-survival, anti-apoptotic state. The natural product curcumin is a known inhibitor of activation of NFκB. Enone analogues of curcumin were compared with curcumin for their abilities to inhibit the TNFα-induced activation of NFκB, using the Panomics' NFκB Reporter Stable Cell Line. The enones tested included curcumin analogues that retained the 7-carbon spacer between the aromatic rings, analogues with a 5-carbon spacer, and analogues with a 3-carbon spacer. Inhibitors of NFκB activation were identified in all three series, a number of which were more active than curcumin. Enone analogues in the series with the 5-carbon spacer were especially active, including members that contained heterocyclic rings. 1,5-Bis(3-pyridyl)-1,4-pentadien-3-one was the most active analogue, IC50 = 3.4 ± 0.2 μM. The most active analogues retain the enone functionality, although some analogues devoid of the enone functionality exhibited activity. The activity of the analogues as inhibitors of the activation of NFκB did not correlate with their anti-oxidant activity. The data suggest that the abilities of curcumin and analogues to prevent the stress-induced activation of NFκB result from the inhibition of specific targets rather than from activity as anti-oxidants.
- Weber, Waylon M.,Hunsaker, Lucy A.,Roybal, C. Nathaniel,Bobrovnikova-Marjon, Ekaterina V.,Abcouwer, Steve F.,Royer, Robert E.,Deck, Lorraine M.,Vander Jagt, David L.
-
p. 2450 - 2461
(2007/10/03)
-
- Method for the preparation of 1,5-bis-aryl-1,4-pentadien-3-ones
-
The invention relates to a method for the preparation of certain substituted bis-arylpentadienones which are useful and valuable intermediates for the preparation of insecticidal amidinohydrazones. The invention further relates to pentadienone substituted
- -
-
-