Steric and substituenteffects on the photochemical reaction of 2,4,6-trialkylphenyl ketones has been investigated. A striking steric effect was observed in the photoreaction of 2,4,6-trialkylbenzophenones. The more hindered the carbonyl group, the more readily photoenolization occurs resulting in intramolecular cyclization leading to benzocyclobutenol derivatives. With 2,4,6-trialkylacetophenones
Nickel‐Catalysis Enabling α‐Alkylation of Ketones by Secondary Alcohols
作者:Amreen K Bains、Ayanangshu Biswas、Abhishek Kundu、Debashis Adhikari
DOI:10.1002/adsc.202200522
日期:2022.8.16
The α-alkylation of ketones utilizing a secondary alcohol has been accomplished by an isolable, bench-stable, inexpensive nickel catalyst affording high yields of β,β-disubstituted products. This report contributes a nickel catalyst in the pool of a few scarce examples of base metal discovered for this purpose. The substrate scope can span a wide range including aliphatic, alicyclic, and cyclic secondary
5-Aryl-1H-pyrazole-3-carboxylic acids as selective inhibitors of human carbonic anhydrases IX and XII
作者:Ilija N. Cvijetić、Muhammet Tanç、Ivan O. Juranić、Tatjana Ž. Verbić、Claudiu T. Supuran、Branko J. Drakulić
DOI:10.1016/j.bmc.2015.05.052
日期:2015.8
Inhibitory activity of a congeneric set of 23 phenyl-substituted 5-phenyl-pyrazole-3-carboxylic acids toward human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms I, II, IX and XII was evaluated by a stopped-flow CO2 hydrase assay. These compounds exerted a clear, selective inhibition of hCA IX and XII over hCAI and II, with Ki in two to one digit micromolar concentrations (4-50 mu M). Derivatives bearing bulkier substituents in para-position of the phenyl ring inhibited hCA XII at one-digit micromolar concentrations, while derivatives having alkyl substituents in both ortho-and meta-positions inhibited hCA IX with Kis ranging between 5 and 25 mu M. Results of docking experiments offered a rational explanation on the selectivity of these compounds toward CA IX and XII, as well as on the substitution patterns leading to best CA IX or CA XII inhibitors. By examining the active sites of these four isoforms with GRID generated molecular-interaction fields, striking differences between hCA XII and the other three isoforms were observed. The field of hydrophobic probe (DRY) appeared significantly different in CA XII active site, comparing to other three isoforms studied. To the best of our knowledge such an observation was not reported in literature so far. Considering the selectivity of these carboxylates towards membrane-associated over cytosolic CA isoforms, the title compounds could be useful for the development of isoform-specific non-sulfonamide CA inhibitors. (C) 2015 Elsevier Ltd. All rights reserved.
The Coupling Action of the Grignard Reagent. VI. A New Synthesis of Hexaalkylbenzils
作者:Reynold C. Fuson、Joseph Corse
DOI:10.1021/ja01276a015
日期:1938.9
Certain Trialkylated Benzenes and their Compounds with Aluminum Chloride and with Aluminum Bromide