100848-88-2Relevant academic research and scientific papers
Synthesis of alkynes from vinyl triflates using tetrabutylammonium fluoride
Okutani, Masaru,Mori, Yuji
, p. 393 - 396 (2015)
A convenient method for the preparation of alkynes and alkynyl esters from ketones and β-keto esters is described which involves the formation of vinyl triflates, followed by elimination with tetrabutylammonium fluoride trihydrate, to give alkynes. Unlike established elimination methods, the method requires neither a strong base nor anhydrous conditions.
Synthesis and in vitro evaluation of novel anti-varicella-zoster virus (VZV) nucleosides
Carangio,McGuigan,Cahard,Andrei,Snoeck,Clercq,Balzarini
, p. 653 - 656 (2001)
A series of alkyl-aryl, -phenoxy, and -thiophenoxy bicyclic furo pyrimidine nucleosides have been successfully synthesised by Pd-coupling of 5-iodo-2′-deoxyuridine (IDU) with terminal alkynes, followed by in situ copper-cyclisation. Synthesised compounds (4a-i) showed an anti-VZV activity at low μM concentration, comparable to that of current treatment acyclovir.
A click-based modular approach to introduction of peroxides onto molecules and nanostructures
Dussault, Patrick H.,Horn, Alissa
, p. 44408 - 44429 (2020)
Copper-promoted azide/alkyne cycloadditions (CuAAC) are explored as a tool for modular introduction of peroxides onto molecules and nanomaterials. Dialkyl peroxide-substituted alkynes undergo Cu(i)-promoted reaction with azides in either organic or biphas
Migratory Hydrogenation of Terminal Alkynes by Base/Cobalt Relay Catalysis
Liu, Bingxue,Liu, Qiang,Liu, Xufang
supporting information, p. 6750 - 6755 (2020/03/13)
Migratory functionalization of alkenes has emerged as a powerful strategy to achieve functionalization at a distal position to the original reactive site on a hydrocarbon chain. However, an analogous protocol for alkyne substrates is yet to be developed. Herein, a base and cobalt relay catalytic process for the selective synthesis of (Z)-2-alkenes and conjugated E alkenes by migratory hydrogenation of terminal alkynes is disclosed. Mechanistic studies support a relay catalytic process involving a sequential base-catalyzed isomerization of terminal alkynes and cobalt-catalyzed hydrogenation of either 2-alkynes or conjugated diene intermediates. Notably, this practical non-noble metal catalytic system enables efficient control of the chemo-, regio-, and stereoselectivity of this transformation.
A Sequential Homologation of Alkynes and Aldehydes for Chain Elongation with Optional 13C-Labeling
Brunner, Andreas,Hintermann, Lukas
, p. 2787 - 2792 (2016/02/27)
Terminal alkynes (RCCH) are homologated by a sequence of ruthenium-catalyzed anti-Markovnikov hydration of alkyne to aldehyde (RCH2CHO), followed by Bestmann-Ohira alkynylation of aldehyde to chain-elongated alkyne (RCH2CCH). Inverting the sequence by starting from aldehyde brings about the reciprocal homologation of aldehydes instead. The use of 13C-labeled Bestmann-Ohira reagent (dimethyl ((1-13C)-1-diazo-2-oxopropyl)phosphonate) for alkynylation provides straightforward access to singly or, through additional homologation, multiply 13C-labeled alkynes. The labeled alkynes serve as synthetic platform for accessing a multitude of specifically 13C-labeled products. Terminal alkynes with one or two 13C-labels in the alkyne unit have been submitted to alkyne-azide click reactions; the copper-catalyzed version (CuAAC) was found to display a regioselectivity of >50 000:1 for the 1,4- over the 1,5-triazine isomer, as shown analytically by 13C NMR spectroscopy.
Decarboxylative elimination of enol triflates as a general synthesis of acetylenes.
Fleming, Ian,Ramarao, Chandrashekar
, p. 1504 - 1510 (2007/10/03)
The enol trifluoromethanesulfonates 4, 8, 12, 17 and 20 of tert-butyl beta-ketodiesters and beta-ketoesters can be hydrolysed to the corresponding carboxylic acids by dissolution in trifluoroacetic acid. The dicarboxylic acids undergo mild decarboxylative elimination to give the acetylenic acids 4 and 9 in aqueous sodium bicarbonate solution at room temperature. Similarly, the monocarboxylic acids give the terminal and mid-chain acetylenes 13, 18, 21, and 24 by refluxing in acetone with potassium carbonate. One of the substituents on the acetylenes can be methyl, primary alkyl, secondary alkyl or ethynyl, and the other can be a carboxylic acid, hydrogen or primary alkyl, but the enol trifluoromethanesulfonates could not be prepared when one of the substituents was tert-butyl, nor when both substituents on the precursor to the acetylene were secondary alkyl.
Decarboxylative elimination of enol triflates as a general synthesis of acetylenes
Fleming, Ian,Ramarao, Chandrashekar
, p. 1113 - 1114 (2007/10/03)
Decarboxylative elimination of a range of enol triflates of β-keto esters gives acetylenes.
Aryl acetylenes as mechanism-based inhibitors of cytochrome P450- dependent monooxygenase enzymes
Foroozesh, Maryam,Primrose, Ginny,Guo, Zuyu,Bell, L. Chastine,Alworth, William L.,Guengerich, F. Peter
, p. 91 - 102 (2007/10/03)
Aryl acetylenes have been investigated as inhibitors of cytochrome P450 (P450)-dependent alkoxyresorufin dealkylation activities in liver microsomes prepared from rats exposed to β-naphthoflavone, isosafrole, or phenobarbital. Many of the acetylenes investigated produce pseudo-first- order time-dependent and NADPH-dependent losses of the dealkylation activities characteristic of mechanism-based irreversible inactivation (suicide inhibition). Replacing the terminal hydrogen of aryl acetylenes with a methyl group to convert ethynes into propynes enhances the inhibition of P450 1A enzymes; in some instances, this modification converts a reversible inhibitor of P450s into a suicide inhibitor. In contrast, ethynes are more effective suicide inhibitors of P450 2B-dependent dealkylations than the corresponding propynes. Aryl acetylenes with an ethynyl group on the 2 position of naphthalene or on the 9 position of phenanthrene and arylalkyl acetylenes with alkyl chains containing 2, 3, or 4 methylene groups are selective inhibitors of P450 2B1/2B2 in liver microsomes from rats. Aryl acetylenes also act as suicide inhibitors of P450 1A2 in human liver microsomes, of purified P450 1A2 from rabbit or rat liver in reconstituted systems, and of purified recombinant human P450 1A2 and 1A1 in reconstituted systems. 4-(1-Propynyl)biphenyl (4PBi) inactivated P450 1A2-dependent ethoxyresourfin deethylation (EROD) activity in human liver microsomes in an NADPH-dependent process (k(inactivation), 0.23 min-1; K1, 2.3 μM). 4PBi also inactivated purified recombinant human P450 1A2 (k(inactivation), 0.24 min-1; K(I), 4.3 μM). In agreement with previous reports [Yun, C.-H., Hammons, G. J., Jones, G., Martin, M. V., Hopkins, N. E., Alworth, W. L., and Guengerich, F. P. (1992) Biochemistry 31, 10556-10563], 2-ethyny]naphthalene (2EN) was not a suicide inhibitor of the P450 1A2 activity in human liver microsomes but did inactivate purified human P450 1A2. Neither 4PBi nor 2EN affected diagnostic activities of human microsomal P450 2E1, 2C9/10, 3A4, or 2C19. In the systems examined, the losses of P450-dependent activity produced by these aryl acetylenes were not accompanied by corresponding decreases in the measured P450 absorption spectra. Thus P450 inactivation by these aryl acetylenes does not involve labeling and destruction of the heme. Incubation of 4PBi with microsomal P450 1A1 or 1A2 from rat liver under conditions that lead to P450-dependent enzyme inactivations generates a 2-biphenylylpropionic acid product. This suggests that the suicide inhibition of P450s by propynylaryl acetylenes proceeds via a methylaryl ketene formed by a 1,2- methyl rearrangement, analogous to the mechanism of suicide inhibition by ethynyl acetylenes that proceed via ketene intermediates formed by 1,2- hydrogen shifts [Ortiz de Montellano, P. R., and Kunze, K. L. (1981) Arch. Biochem. Biophys. 209, 710-712].
