22238-17-1Relevant articles and documents
Synthesis of thiophene and NO-curcuminoids for antiinflammatory and anti-cancer activities
Ahmed, Mahera M.,Khan, M. Akram,Rainsford, Kim Drummond
, p. 1483 - 1501 (2013/04/23)
In search of better NSAIDs four novel nitric oxide donating derivatives of curcumin (compounds 9a-d), and four thiophene curcuminoids (compounds 10a-c, 11) have been synthesised. The cytotoxic effects of these compounds along with the lead compound curcumin (7) and their effect on the production of the reactive oxygen species nitric oxide and pro-inflammatory cytokines IL-1β, TNF-α and chemokine CXCL-8 were evaluated using human monocytic THP-1 and colon adenocarcinoma CACO-2 cell lines. All of the nitric oxide donating curcuminoids 9a-d and the thiophene curcuminoids 10a-c and 11 were non-cytotoxic to THP-1 cells over a concentration range of 10-100 μM and compared with curcumin compounds 10b and 10c, were more toxic. In CACO-2 cells, 10b and 11 appeared to be non-toxic at 10 to 50 μM, whereas 10a and 10c were non-cytotoxic at 10 μM only. These results clearly indicate that the introduction of a nitroxybutyl moiety to curcumin and replacement of phenyl rings with thiophene units reduces the cytotoxic effect of the parent curcumin, whereas a methyl substituted thiophene increases the cytotoxic effects. In THP-1 cells, drugs 10a and 11 significantly decreased IL-1-β production at their non-cytotoxic concentrations, whereas, they did not decrease TNF-α production in CACO-2 cells. Compound 11 showed a significant decrease in CXCL-8 production.
A new method for the chemoselective reduction of aldehydes and ketones using boron tri-isopropoxide, B(OiPr)3: Comparison with boron tri-ethoxide, B(OEt)3
Uysal, Burcu,Oksal, Birsen S.
body text, p. 681 - 685 (2012/06/18)
A chemoselective Meerwein-Ponndorf-Verley reduction process of various aliphatic and allylic α,β-unsaturated aldehydes and ketones is described. This chemoselective reduction is catalysed by boron triisopropoxide B(Oi Pr)3. Kinetics of reduction of aldehydes and ketones to corresponding alcohols were also examined and rate constant of each carbonyl compounds were measured. Rate constant and reduction yield of each carbonyl compounds in the presence of B(Oi Pr)3 were compared with those in the presence of B(OEt)3. The alcohols that are the reduction product were analysed by GC-MS. The rate constants and alcohol yields were found to be higher with B(OEt)3 than with B(Oi Pr) 3. The mechanism proposed involves a six-membered transition state in which both the alcohol and the carbonyl are coordinated to the same boron centre of a boron alkoxide catalyst. Indian Academy of Sciences.
Application of Mechanochemical Catalysis to the Synthesis of Boric Acid Esters
Molchanov,Goidin,Golovin,Zolotovskaya,Bogdanov,Volodin
, p. 536 - 541 (2008/10/08)
The syntheses of triisopropyl borate and other boric acid esters under conditions of mechanochemical activation (MCA) with the use of zeolite catalysts were presented. The proposed method showed short synthesis times, low energy consumption, higher yields of target products, and the absence of byproducts. The mechanism of the catalytic esterification of boric acid under conditions of MCA was described. The conversion was no > 30%. The introduction of zeolites into the reaction zone increased the degree of conversion because of water removal from the reaction medium. Lower conversions of 2-butanol were related to its high viscosity, as a result of which the intensity of MCA was considerably decreased.
Convergent synthesis of alpha -aryl- beta -ketonitriles
-
, (2008/06/13)
The present invention relates to processes for the production of alpha -aryl- beta -ketonitriles, which serve as synthetic intermediates in the preparation of a series of biologically important molecules such as corticotropin releasing factor (CRF) receptor antagonists.
Addition compounds of alkali-metal hydrides. 24. A general method for preparation of potassium trialkoxyborohydrides. A new class of reducing agents
Brown, Herbert C.,Cha, Jin Soon,Nazer, Behrooz
, p. 2929 - 2931 (2008/10/08)
The generality of the synthesis of potassium triisopropoxyborohydride, stabilized toward disproportionation by storing over excess potassium hydride, was examined with seven additional organoborates of varying steric requirements. The reaction of trimethoxy- and triethoxyborane with potassium hydride proceeded readily at room temperature, but the products could not be stabilized by the presence of excess potassium hydride. Triphenoxyborane reacted readily, even at -10°C, and stabilization was achieved. Tri-sec-butoxy- and tricyclopentoxyborane required refluxing in THF for 12-24 h, and the products were stabilized over potassium hydride. Finally, the reactions of tris(2-methylcyclohexoxy)- and tri-tert-butoxyborane were even slower, requiring a number of days for completion. Both products were stabilized toward disproportionation over potassium hydride. Indeed, potassium tri-tert-butoxyborohydride was quite stable toward disproportionation without excess potassium hydride. The stereoselectivities of these reagents in the reduction of representative cyclic ketones were examined. The stereoselectivities varied in an erratic manner with the steric requirements of the alkoxy group and did not approach the stereoselectivities previously achieved with lithium tri-sec-butylborohydride and lithium trisiamylborohydride.
