Investigation of the non-classical carbocations stability obtained from the epoxide ring opening

• Grant number: 22/16223-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): January 01, 2023
• Effective date (End): December 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Claudio Francisco Tormena
• Grantee: Leonardo Fuzato Ferreira Lopes
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 20/10246-0 - Nuclear magnetic resonance spectroscopy: from pulse sequences to structural assignments, AP.TEM

Abstract

It is proposed to investigate the stability of non-classical carbocations formed by the opening reaction of alpha-pinene oxide in acidic medium in solvents of different polarities and at different temperatures. The structures and stability of the possible carbocations (Scheme 1) will be experimentally determined indirectly through the unequivocal determination of the structures and proportion of the products.The characterization will be performed applying Nuclear Magnetic Resonance spectroscopy using 1H, 13C, HSQC, HMBC, COSY and NOESY spectra. The isomerization mechanisms and reaction path for the formation of intermediates (carbocations), transition states and products will be determined through quantum-mechanical calculations using DFT theory with different functionals and basis sets. The joint analysis of all these data will allow evaluating which carbocation(s) will be formed and what is the effect of solvent and temperature on their stability.