Multicomponent Catalytic ReactionsTheoretical and Experimental Studies

  1. Pauze, Martin Paul
Dirigida por:
  1. Belén Martín Matute Director/a
  2. Enrique Gómez Bengoa Director

Universidad de defensa: Universidad del País Vasco - Euskal Herriko Unibertsitatea

Fecha de defensa: 28 de septiembre de 2021

Tribunal:
  1. Anne Linusson Presidente/a
  2. Abel de Cózar Ruano Secretario
  3. Christian Skold Vocal

Tipo: Tesis

Teseo: 156714 DIALNET lock_openADDI editor

Resumen

In this thesis, Density Functional Theory (DFT) methods have been applied to study the mechanisms of three different multicomponent organic reactions. Also, a new synthetic procedure for the preparation of quinolinium salts is presented, and its mechanism also studied by DFT calculations. The thesis summarizes the work realized in two universities, and is divided in the following way: The first part of the thesis concerns the development of an experimentally simple, but mechanistically complex, reaction for the formation of quaternary quinolinium salts catalyzed by palladium salts. This multicomponent process uses readily available propylamine and its derivatives as starting materials. Through DFT studies a mechanism through the activation of two aliphatic C¿H bonds is proposed. The second part focuses on the mechanistic investigation of a three-components reaction, namely terminal alkynes, CO2 and allylic chlorides, mediated by an N-heterocyclic carbene catalyst that yields propargylic esters. By DFT calculations, the rate-limiting step was identified to be the reaction between the carboxylated catalyst and the allylic chloride. Through DFT, we were also able to understand the limitations of this reaction. The mechanism of a multicomponent reaction in which allylic alcohols are transformed into ¿-functionalized carbonyls was also investigated. The reaction relies on an umpolung strategy that enables to react enol intermediates with different nucleophiles. By DFT studies, a mechanism via enolonium intermediates is proposed, which provides an understanding of the selectivity of the reaction. The final chapter of the thesis deals with another multicomponent solvent-free reaction for synthesizing propargylamines catalyzed by manganese via a KA2 coupling. DFT studies were undertaken and a mechanism via manganese phenylacetylide species is proposed.