1666-04-2Relevant articles and documents
A modified synthesis of O-hydroxyaryl aldehydes
Wang,You,Meng,Mintz,Bu
, p. 1757 - 1760 (1994)
A modified method for the synthesis of o-hydroxyaryl aldehydes in moderate yields has been developed by treating aryloxymagnesium bromides with formaldehyde using triethylamine in place of hexamethylphosphoric triamide (HMPA).
Inhibition of Urease, a Ni-Enzyme: The Reactivity of a Key Thiol With Mono- and Di-Substituted Catechols Elucidated by Kinetic, Structural, and Theoretical Studies
Mazzei, Luca,Contaldo, Umberto,Musiani, Francesco,Cianci, Michele,Bagnolini, Greta,Roberti, Marinella,Ciurli, Stefano
supporting information, p. 6029 - 6035 (2021/02/09)
The inhibition of urease from Sporosarcina pasteurii (SPU) and Canavalia ensiformis (jack bean, JBU) by a class of six aromatic poly-hydroxylated molecules, namely mono- and dimethyl-substituted catechols, was investigated on the basis of the inhibitory efficiency of the catechol scaffold. The aim was to probe the key step of a mechanism proposed for the inhibition of SPU by catechol, namely the sulfanyl radical attack on the aromatic ring, as well as to obtain critical information on the effect of substituents of the catechol aromatic ring on the inhibition efficacy of its derivatives. The crystal structures of all six SPU-inhibitors complexes, determined at high resolution, as well as kinetic data obtained on JBU and theoretical studies of the reaction mechanism using quantum mechanical calculations, revealed the occurrence of an irreversible inactivation of urease by means of a radical-based autocatalytic multistep mechanism, and indicate that, among all tested catechols, the mono-substituted 3-methyl-catechol is the most efficient inhibitor for urease.
Enantioselective Phenolic α-Oxidation Using H2O2 via an Unusual Double Dearomatization Mechanism
McLaughlin, Michael F.,Massolo, Elisabetta,Liu, Shubin,Johnson, Jeffrey S.
, (2019/02/14)
Feedstock aromatic compounds are compelling low-cost starting points from which molecular complexity can be generated rapidly via oxidative dearomatization. Oxidative dearomatizations commonly rely heavily on hypervalent iodine or heavy metals to provide the requisite thermodynamic driving force for overcoming aromatic stabilization energy. This article describes oxidative dearomatizations of 2-(hydroxymethyl)phenols via their derived bis(dichloroacetates) using hydrogen peroxide as a mild oxidant that intercepts a transient quinone methide. A stereochemical study revealed that the reaction proceeds by a new mechanism relative to other phenol dearomatizations and is complementary to extant methods that rely on hypervalent iodine. Using a new chiral phase-transfer catalyst, the first asymmetric syntheses of 1-oxaspiro[2.5]octa-5,7-dien-4-ones were reported. The synthetic utility of the derived 1-oxaspiro[2.5]octadienones products is demonstrated in a downstream complexity-generating transformation.
Directed Remote Lateral Metalation: Highly Substituted 2-Naphthols and BINOLs by In Situ Generation of a Directing Group
Patel, Jignesh J.,Laars, Marju,Gan, Wei,Board, Johnathan,Kitching, Matthew O.,Snieckus, Victor
supporting information, p. 9425 - 9429 (2018/07/29)
A general synthesis of highly substituted 2-naphthols based on a new carbanionic reaction sequence is demonstrated. The reaction exploits the dual nature of lithium bases consisting of consecutive ring opening of readily available coumarins with either LiNEt2 or LiNiPr2 into Z-cinnamamides, thus generating a directing group in situ and allowing, by conformational freedom, a lateral directed remote metalation for ring closure to give the aryl 2-naphthols in good to excellent yields. These transformations can be combined to provide a more efficient one-pot process. Mechanistic insight into the remote lateral metalation step, demonstrating the requirement of Z-cinnamamide, is described. Application of this methodology to the synthesis of highly substituted 3,3′-diaryl BINOL ligands is also reported.
