Investigation of the mechanism of transition metal-catalyzed multicomponent reactions by Mass Spectrometry

• Grant number: 16/03036-4
• Support Opportunities: Scholarships abroad - Research
• Start date: July 25, 2018
• End date: June 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Antônio Eduardo Miller Crotti
• Grantee: Antônio Eduardo Miller Crotti
• Host Investigator: Jason Scott Mcindoe
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of Victoria (UVic), Canada

Abstract

Knowledge of reaction mechanisms provides the basis for the development of more sustainable chemical processes that will hopefully improve the yields of desired products and reduce waste production and energy consumption. In the last decade, electrospray ionization mass spectrometry (ESI-MS) and its sequential version (ESI-MS/MS) have emerged as powerful tools to investigate the mechanisms of many chemical reactions. These techniques have enabled analysis of intermediates with very short lifetimes, which would be impossible to achieve by other techniques (e.g. NMR, IR, and UV/vis). The use of charged or chargeable tags in reagents and/or catalysts as well as advances in the field of mass spectrometry (development of the Venturi Easy Ambient Sonic-Spray Ionization (V-EASI) and Pressurized Sample Infusion (PSI)) have allowed for online and real-time monitoring of reagents, products, and even species with lifetime in the scale of milliseconds-such tags and techniques make direct transfer of chemical species from the reaction vessel to the gas phase possible. Despite the considerable number of papers reporting on the use of ESI-MS/MS to detect and characterize intermediates of organometallic-catalyzed organic reactions, this technique has been little explored to study mechanisms of transition metal-catalyzed multicomponent reactions (MCRs). This project proposes the mechanistic study of a cobalt-mediated MCR. This MCR has been recently demonstrated to favor the fast and efficient synthesis of 2,3-di- e 2,2,3-trisubstituted 3-methoxycarbonyl-³lactones from dimethyl itaconate, an aromatic aldehyde, and an aromatic halide. The proposed mechanistic study will combine real-time ESI-MS/MS data with data obtained by spectroscopic techniques such as NMR, IR, and UV/vis. Depending on the progress of the project, other transition metal-catalyzed MCRs could also be investigated. (AU)