81854-47-9Relevant academic research and scientific papers
Catalyst-free hydrochlorination protocol for terminal arylalkynes with hydrogen chloride
Xu, Cai-Xia,Ma, Cun-Hua,Xiao, Fu-Rong,Chen, Hong-Wei,Dai, Bin
, p. 1683 - 1685 (2016/11/12)
We present a simple and straightforward protocol for hydrochlorination of terminal arylalkynes to vinyl chlorides using hydrogen chloride under mild reaction conditions. This protocol does not involve any metal catalysts or additives. It is simple, inexpensive, and easy to prepare, and exhibits good reaction activity. The hydrochlorination proceeds smoothly to yield unique regioselective products via the Markovnikov addition rule.
Synthesis, stereocontrol and structural studies of highly luminescent chiral tris-amidepyridyl-triazacyclononane lanthanide complexes
Neil, Emily R.,Funk, Alexander M.,Yufit, Dmitry S.,Parker, David
, p. 5490 - 5504 (2014/04/03)
The configuration of the remote amide chiral moiety determines the helicity of the metal complex in Ln(iii) complexes of nonadentate N6O 3 ligands based on triazacyclononane. Solution NMR studies revealed the presence of a dominant isomer whose proportion varies from 9:1 to 4:1 from Ce to Yb and X-ray crystallographic studies at 120 K of the Yb and two enantiomeric Eu complexes confirmed the configuration as S-Δ-λ in the major isomer. Global minimisation methods allowed magnetic susceptibility and electronic relaxation times of the lanthanide ions to be estimated by analysis of variable field longitudinal relaxation rate (R1) data sets. A set of four europium complexes, containing different para-substituted pyridinyl-aryl groups, exist as one major isomer (15:1), and absorb light strongly via an ICT transition in the range 320 to 355 nm (ε = 55 to 65000 M-1 cm-1). The two examples absorbing light at 332 nm, possess overall emission quantum yields of 35 and 37% in aerated water, making these systems as bright as any Eu complex in solution. This journal is the Partner Organisations 2014.
Palladium-catalyzed coupling between aryl halides and trimethylsilylacetylene assisted by dimethylaminotrimethyltin
Cai, Liangzhen,Yang, Dujuan,Sun, Zhonghua,Tao, Xiaochun,Cai, Lisheng,Pike, Victor W.
experimental part, p. 1059 - 1062 (2012/01/04)
Palladium-catalyzed coupling between aryl halides, especially less reactive ones or N-heteroaryls, and trimethylsilylacetylene in the presence of dimethylaminotrimethyltin generated the coupled products in high yields. The reaction does not need CuI and base as auxiliary agents.
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].
PALLADIUM-CATALYSED REDUCTIVE ADDITION OF ARYL IODIDES TO ARYL AND ALKYLETHYNYLSILANES: A STEREO AND REGIOSELECTIVE ROUTE TO FUNCTIONALIZED 2,2-DISUBSTITUTED VINYLSILANES
Arcadi, A.,Cacchi, S.,Marinelli, F.
, p. 6397 - 6400 (2007/10/02)
Aryl and alkylethynylsilanes are converted into 2,2-disubstituted vinylsilanes containing various common functional groups in the presence of aryl iodides, a palladium catalyst, formic acid, and a tertiary or secondary amine with high stereoselectivity an
