Chemisty Ph.D. Dissertation

Abstract

Pincer complexes moieties have attracted much attention in the past years. They have been proven they are highly active catalysts in many different known transitions metal-catalyzed organic reactions and some unpredictable organic transformations. In this thesis, well-defined and air-stable PN3-pincer manganese (II) complexes were synthesized and used for the hydrogenation of aldehydes into alcohols under mild conditions using MeOH as a solvent.

This protocol is applicable for a wide range of aldehydes containing various functional groups. Importantly, α,β-Unsaturated aldehydes, including ynals, are hydrogenated with the C=C double bond/CΞC triple bond intact. Our methodology was demonstrated for biomass derived feedstock such as furfural and 5-formyl furfural to furfuryl alcohol and 5-(hydroxymethyl)furfuryl alcohol respectively.

Using air stable, well-defined PN3-pincer manganese (II) complex as a catalyst, various aldehydes are easily converted directly into secondary imines using NH3 as a nitrogen source under hydrogen pressure in one pot. More importantly, using the same catalyst, various benzylamines undergo dehydrogenative homocoupling to form an imine product exclusively.

Third project. A well-defined and air-stable PN3-pincer manganese (II) complexes were synthesized for the hydrogenation of nitroarenes to amine, various nitroarenes are hydrogenated using MeOH as a solvent.
Fourth project. A well-defined and air-stable PN3-pincer manganese (II) complexes were synthesized for the hydration of nitriles to amide, using iPrOH as a solvent and water as hydration source.