Selective Nuclear Magnetic Resonance Experiments for Sign-Sensitive Determination of Heteronuclear Couplings: Expanding the Analysis of Crude Reaction Mixtures

Autor(es)

Dal Poggetto, Guilherme ^[1] ; Soares, Joao Vitor ^[1] ; Tormena, Claudio F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Chem, UNICAMP, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Analytical Chemistry; v. 92, n. 20, p. 14047-14053, OCT 20 2020.
• Citações Web of Science: 0

Resumo

State-of-the-art nuclear magnetic resonance (NMR) selective experiments are capable of directly analyzing crude reaction mixtures. A new experiment named HD-HAPPY-FESTA yields ultrahigh-resolution total correlation subspectra, which are suitable for sign-sensitive determination of heteronuclear couplings, as demonstrated here by measuring the sign and magnitude for proton-fluorine couplings (J(HF)) from major and minor isomer products of a two-step reaction without any purification. Proton - fluorine couplings ranging from 51.5 to -2.6 Hz could be measured using HD-HAPPY-FESTA, with the smallest measured magnitude of 0.8 Hz. Experimental J(HF) values were used to identify the two fluoroketone intermediates and the four fluoroalcohol products. Results were rationalized and compared with the density functional theory (DFT) calculations. Experimental data were further compared with the couplings reported in the literature, where pure samples were analyzed. (AU)

• Processo FAPESP: 18/19253-0 - Novas sequências de pulso e ferramentas de processamento para experimentos multidimensionais em RMN: Aplicação em análises de misturas de produtos naturais
• Beneficiário: Guilherme Fonseca Dal Poggetto
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/08541-6 - Ressonância magnética nuclear: além da determinação estrutural
• Beneficiário: Claudio Francisco Tormena
• Modalidade de apoio: Auxílio à Pesquisa - Temático