Dynamics behavior in the border area between concerted syn-elimination (Ei) and stepwise elimination (E1)

• Grant number: 19/14609-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: November 01, 2019
• End date: October 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Marco Antonio Barbosa Ferreira
• Grantee: Meire Yasuko Kawamura
• Supervisor: Robert Paton
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Colorado State University, United States
• Associated to the scholarship: 17/01754-0 - Experimental and theoretical studies on cycloaddition (3 + 2) reactions of azides to nitro-olefins, BP.DR

Abstract

Exploration of chemical transformation in a time-resolved fashion by introduction of molecular dynamics trajectory simulations has boosted studies of chemical dynamics. These simulations disclose how the motion and momenta of molecules induce the reactivity and selectivity of chemical reactions. A class of reaction that could be favored by molecular dynamics is the syn-elimination (Ei mechanism), the TS for this transformation is believed to pass through a concerted process with cyclic TS. More specifically, DFT studies performed by our research group about intramolecular elimination step of 1,3-dipolar cycloaddition reaction of nitro-olefins and azides showed an intriguing transition state, it seems that the mechanism is in the border of concerted syn-elimination (Ei) and stepwise E1 elimination by formation of a carbocation that rapidly abstract the proton. Molecular dynamics could be a powerful tool to clarify this type of process where the mechanism is not fully understood by transition state theory. Moreover, dynamics factors could predict the stereoselective of syn-elimination reactions, which could potentially provide Z/E double bonds. Therefore, we intend to investigate the elimination step of 1,3-dipolar cycloaddition of nitro-olefins and azides and furthermore, the stereoselective syn-elimination of more complex substrate to afford tetrasubstituted olefins, in order to analyze the factors that govern the selectivity of the process.