7295-52-5Relevant academic research and scientific papers
Ring size and nothing else matters: unusual regioselectivity of alkyne hydration by NHC gold(i) complexes
Ageshina, Alexandra A.,Asachenko, Andrey F.,Chesnokov, Gleb A.,Minaeva, Lidiya I.,Nechaev, Mikhail S.,Philippova, Anna N.,Rzhevskiy, Sergey A.,Topchiy, Maxim A.
supporting information, p. 5686 - 5689 (2021/06/16)
We have investigated the role of ring sizes and substituents in NHC ligands in some (NHC)Au(i) complexes in the hydration of internal alkynes. Despite the fact that using (NHC)Au(i) complexes in the hydration of diarylacetylenes leads to Markovnikov-type products, the precise tuning of ligands allows changing the regioselectivity in arylalkylacetylene hydration to the anti-Markovnikov-type.
Gram-Positive and Gram-Negative Antibiotic Activity of Asymmetric and Monomeric Robenidine Analogues
Russell, Cecilia C.,Stevens, Andrew,Pi, Hongfei,Khazandi, Manouchehr,Ogunniyi, Abiodun D.,Young, Kelly A.,Baker, Jennifer R.,McCluskey, Siobhann N.,Page, Stephen W.,Trott, Darren J.,McCluskey, Adam
, p. 2573 - 2580 (2018/11/27)
Desymmetrisation of robenidine (1: N′,2-bis((E)-4-chlorobenzylidene)hydrazine-1-carboximidhydrazide) and the introduction of imine alkyl substituents gave good antibiotic activity. Of note was the increased potency of two analogues against vancomycin-resistant Enterococci (VRE), one of which returned a MIC of 0.5 μg mL?1. Five analogues were found to be equipotent or more potent than the lead 1. Introduction of an indole moiety resulted in the most active robenidine analogue against methicillin-resistant S. aureus (MRSA), with a MIC of 1.0 μg mL?1. Imine C=NH isosteres (C=O/C=S) were inactive. Monomeric analogues were 16–64 μg mL?1 active against MRSA and VRE. An analogue that lacks the terminal hydrazide NH moiety showed modest Gram-negative activity at 64 μg mL?1. A 4-tert-butyl analogue was shown to be active against both Gram-positive and -negative strains at 16–64 μg mL?1. In general, additional modifications with aromatic moieties was poorly tolerated, except with concomitant introduction of an imine C-alkyl group. The activity of these analogues against MRSA and VRE ranged from 8 μg mL?1 to inactive (MIC>128 μg mL?1) with the naphthyl and indole analogues. Gram-negative activity was most promising with two compounds at 16 μg mL?1 against E. coli. Against P. aeruginosa, the highest activity observed was with MIC values of 32 μg mL?1 with another two analogues. Combined, these findings support the further development of the (E)-2-benzylidenehydrazine-1-carboximidamide scaffold as a promising scaffold for the development of antibiotics against Gram-positive and Gram-negative strains.
Palladium and visible-light mediated carbonylative Suzuki-Miyaura coupling of unactivated alkyl halides and aryl boronic acids
Roslin, Sara,Odell, Luke R.
supporting information, p. 6895 - 6898 (2017/07/10)
Herein, a simple and efficient method for the palladium-catalyzed carbonylation of aryl boronic acids with unactivated alkyl iodides and bromides under visible-light irradiation, ambient temperature and low CO-pressure is presented. Notably, the procedure uses readily available equipment and an inexpensive palladium catalyst to generate the key alkyl radical intermediate. These mild conditions enabled the synthesis of a range of functionalized aryl alkyl ketones including the antipsychotic drug, melperone.
Dehydrogenative cross-coupling of primary and secondary alcohols
Musa, Sanaa,Ackermann, Lutz,Gelman, Dmitri
supporting information, p. 3077 - 3080 (2014/03/21)
Homo-and cross-coupling of alcohols resulting in the formation of the corresponding ketones in very good to excellent yield was realized through the one-pot sequence of dehydrogenation/ aldol condensation/hydrogenation accompanied by the release of molecular hydrogen. The dehydrogenation and hydrogenation steps are catalyzed by the previously reported ruthernium-and iridiumbased ligand-metal cooperating catalysts.
Reductive bromine atom-transfer reaction
Sumino, Shuhei,Fusano, Akira,Ryu, Ilhyong
supporting information, p. 2826 - 2829 (2013/07/19)
Atom-transfer radical (ATR) reactions of alkenes with R-X usually give products having new C-C and C-X bonds at the adjacent carbons. However, when the reaction was carried out under irradiation using a low-pressure Hg lamp, addition/reduction products were obtained in good yield. Hydrogen bromide, formed by H-abstraction of a bromine radical from alkenes, is likely to play a key role in the reductive ATR reaction.
Practical one-pot preparation of ketones from aryl and alkyl bromides with aldehydes and DIH via Grignard reagents
Dohi, Souya,Moriyama, Katsuhiko,Togo, Hideo
experimental part, p. 6557 - 6564 (2012/08/27)
Various diaryl ketones, alkyl aryl ketones, and dialkyl ketones were efficiently prepared in good yields by the reactions of the Grignard reagents derived from aryl or alkyl bromides, followed by the reactions with aromatic or aliphatic aldehydes and the subsequent treatment with 1,3-diiodo-5,5- dimethylhydantoin and K2CO3, in a one-pot method. The same treatment of aromatic bromides bearing electron-withdrawing groups, such as ester, nitrile, ketone, and nitro groups with i-PrMgCl·LiCl or PhMgCl instead of Mg, also provided the corresponding diaryl and alkyl aryl ketones in good yields. The above methods are simple and practical transition-metal-free methods for the preparation of various diaryl ketones and alkyl aryl ketones bearing electron-rich aromatic groups and electron-deficient aromatic groups, as well as dialkyl ketones.
Block of human NaV 1.5 sodium channels by novel α-hydroxyphenylamide analogues of phenytoin
Lenkowski, Paul W.,Ko, Seong-Hoon,Anderson, James D.,Brown, Milton L.,Patel, Manoj K.
, p. 635 - 644 (2007/10/03)
Voltage-gated sodium (Na) channels are a critical component of electrically excitable cells. Phenytoin (diphenylhydantoin, DPH) is an established sodium channel blocker and is a useful anticonvulsant and class 1b antiarrhythmic, and has been effectively used in the treatment of neuropathic pain. In this study, we have synthesized novel α-hydroxyphenylamide analogues of diphenylhydantoin and examined their ability to inhibit human Nav1.5 sodium channels expressed in Chinese Hamster Ovary (CHO-K1) cells. Phenyl ring substitutions were examined including para-methyl, para-fluoro, para-chloro, ortho-chloro and meta-chloro. We have found that phenyl ring substitutions with electron withdrawing properties resulted in compounds with greater activity. In comparison to diphenylhydantoin, the novel chloro-substituted α-hydroxyphenylamide compounds produced as much as a 20-fold greater tonic and frequency-dependent blockade of Nav1.5 channels with an IC50 value of 14.5μM. In addition, the chloro-substitutions have position specific state dependent blocking properties. The ortho-, meta- and para-chloro substitutions have an 8-, 13- and 3-fold increased affinity for the inactivated state, respectively. Molecular modeling suggests that these differences in affinity are due to a direct interaction with the receptor. Comparing models of diphenylhydantoin to the novel α-hydroxyphenlyamide compound suggests that the increased activity may be due to an optimized phenyl ring position and increased molecular volume. This information may be useful in the development of more potent sodium channel blockers.
Highly efficient chromium-catalyzed oxidation of secondary benzylic alcohols by aqueous 70% tert-butyl hydroperoxide
Muzart,N'Ait Ajjou
, p. 785 - 787 (2007/10/02)
The oxidation of secondary benzylic alcohols to ketones by the chromium(VI) oxide/tert-butyl hydroperoxide system is compatible with the presence of methyl, halide, methoxy, acetoxy or nitro substituents on the aryl group and of an unsaturation on the alkyl side chain. Benzyl alcohol led to a mixture of benzaldehyde and benzoic acid.
