Nuclear Magnetic Resonance spectroscopy and theoretical calculation for real-time reaction monitoring and mechanistic investigation

• Grant number: 16/24331-4
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): March 01, 2017
• Effective date (End): November 30, 2021
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal researcher: Claudio Francisco Tormena
• Grantee: Uenifer Rodrigues Couto
• Home Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 15/08541-6 - Nuclear magnetic resonance spectroscopy: beyond molecular structure assignment, AP.TEM

Abstract

One of the most important subjects in organic chemistry is the investigation of reactional mechanism involved in chemical transformations. Its elucidation provides important information, such as selectivity and reactional yield for the reaction under analysis. These mechanisms can be investigated through real-time reaction monitoring, providing kinetics parameters and the unequivocal assignment of intermediate and product structures, giving the new connectivity between atoms generated during reaction. While the information about the structure for the stable intermediates and products can be easily determined through Nuclear Magnetic Resonance spectroscopy, the transition state structure involved in reaction pathway can only be achieved when quantum mechanics calculation is applied. In the present proposal, NMR spectroscopy and quantum mechanics calculation were joined to elucidate the reactional mechanism involved in the Gewald reaction, which is a multicomponent transformation to insert sulphur atom resulting in 2-aminothiophene derivatives. This reaction was chosen because it is a versatile procedure to insert sulphur atom in mild conditions, but, the way for such sulphur insertion is far to be understood. Several substrates involved in Gewald reaction containing donor and withdrawing electron groups will be used to determine the kinetics and thermodynamics parameters involved on Gewald reaction.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COUTO, UENIFER RODRIGUES; NAVARRO-VAZQUEZ, ARMANDO; TORMENA, CLAUDIO FRANCISCO. Unexpected behavior of the (3)J(CH) coupling constant in unsaturated compounds. Magnetic Resonance in Chemistry, v. 57, n. 11, p. 939-945, NOV 2019. Web of Science Citations: 0.