Organic synthesis in mass spectrometry: 1. Mechanistic studies of iodine (III)-promoted oxidations. 2. Synthesis of new MALDI-MS matrices.

Abstract

Hypervalent iodine chemistry has gained a significant amount of attention among chemists over the last decades. Due to their great potential as reagents and catalysts in organic synthesis, detailed understanding of the mechanisms by which these reactions occur is crucial for the advance of this branch of organic chemistry. In this sense, mass spectrometry has emerged as a powerful toll in the elucidation of reaction mechanisms, making it possible not only the detection of reagents and products, but also transient reaction intermediates. A significant advance in the use of mass spectrometry was its association with ion mobility spectrometry, making the resolution of isomeric compounds possible. Thus, in this project we intend to study in depth the mechanisms by which several iodine (III)-mediated reactions occur by ESI-MS. To this end, we will synthesize charge-tagged iodoarenes, which will act as pre-catalysts. In the next phase of this project, we will synthesize chiral charge-tagged iodoarenes, and use them as pre-catalysts in asymmetric version of these oxidations; in this case, the mechanistic studies will be performed by ESI-MS as well as by ESI-MS coupled with IMS.In a second part of this work, we intend to evaluate novel MALDI-MS matrices. Despite wide availability of commercial matrices, their structural and functional diversities are relatively small, and so are efforts in the development of matrices based on non-conventional organic acids and bases. Thus, we intend to synthesize and evaluate the potential of new matrices based on several different 1-alkylpyridinium salts. Moreover, we intend to synthesize new matrices based on cinnamic acids using Morita-Baylis-Hillman adducts as starting materials.