1395103-14-6Relevant articles and documents
Lewis or Br?nsted? A Rectification of the Acidic and Aromatic Nature of Boranol-Containing Naphthoid Heterocycles
Ang, Hwee Ting,Ferguson, Michael J.,Hall, Dennis G.,Johnson, Matthew A.,Kazmi, M. Zain H.,Paladino, Marco,Rygus, Jason P. G.
supporting information, p. 10143 - 10156 (2021/07/21)
Boron-containing heterocycles are important in a variety of applications from drug discovery to materials science; therefore a clear understanding of their structure and reactivity is desirable to optimize these functions. Although the boranol (B-OH) unit of boronic acids behaves as a Lewis acid to form a tetravalent trihydroxyborate conjugate base, it has been proposed that pseudoaromatic hemiboronic acids may possess sufficient aromatic character to act as Br?nsted acids and form a boron oxy conjugate base, thereby avoiding the disruption of ring aromaticity that would occur with a tetravalent boronate anion. Until now no firm evidence existed to ascertain the structure of the conjugate base and the aromatic character of the boron-containing ring of hemiboronic "naphthoid"isosteres. Here, these questions are addressed with a combination of experimental, spectroscopic, X-ray crystallographic, and computational studies of a series of model benzoxazaborine and benzodiazaborine naphthoids. Although these hemiboronic heterocycles are unambiguously shown to behave as Lewis acids in aqueous solutions, boraza derivatives possess partial aromaticity provided their nitrogen lone electron pair is sufficiently available to participate in extended delocalization. As demonstrated by dynamic exchange and crossover experiments, these heterocycles are stable in neutral aqueous medium, and their measured pKa values are consistent with the ability of the endocyclic heteroatom substituent to stabilize a partial negative charge in the conjugate base. Altogether, this study corrects previous inaccuracies and provides conclusions regarding the properties of these compounds that are important toward the methodical application of hemiboronic and other boron heterocycles in catalysis, bioconjugation, and medicinal chemistry.
Light-Induced Tetrazole-Quinone 1,3-Dipolar Cycloadditions
Ortiz-Rojano, Laura,Rojas-Martín, Jaime,Rodríguez-Diaz, Ciro,Carre?o, M. Carmen,Ribagorda, Maria
supporting information, p. 15050 - 15054 (2019/11/13)
Quinones were firstly used as dipolarophiles in a photoclick 1,3-cycloaddition with 2,5-diaryltetrazoles, as photoactivatable predipoles, providing a novel and efficient access to three types of pyrazole-fused quinones (indazoledione derivatives). Distinc
Tetrazole-Based Probes for Integrated Phenotypic Screening, Affinity-Based Proteome Profiling, and Sensitive Detection of a Cancer Biomarker
Cheng, Ke,Lee, Jun-Seok,Hao, Piliang,Yao, Shao Q.,Ding, Ke,Li, Zhengqiu
supporting information, p. 15044 - 15048 (2017/11/20)
Target-identification phenotypic screening has been a powerful approach in drug discovery; however, it is hindered by difficulties in identifying the underlying cellular targets. To address this challenge, we have combined phenotypic screening of a fully functionalized small-molecule library with competitive affinity-based proteome profiling to map and functionally characterize the targets of screening hits. Using this approach, we identified ANXA2, PDIA3/4, FLAD1, and NOS2 as primary cellular targets of two bioactive molecules that inhibit cancer cell proliferation. We further demonstrated that a panel of probes can label and/or image annexin A2 (a cancer biomarker) from different cancer cell lines, thus providing opportunities for potential cancer diagnosis and therapy.
