Ruthenium Catalysed Transformations of Amines and Alcohols

Abstract

This thesis describes the chemistry developed during a study of ruthenium catalysed reactions of amines and alcohols.

Chapter 2 describes a one-pot two-step process to access primary amines using borrowing hydrogen methodology with masked ammonia sources. This unique approach allows selective access to primary amines without the over alkylation seen when using other ammonia sources. Furthermore, the borrowing hydrogen reaction can be coupled with an in-situ palladium catalysed hydrogenolysis/deprotection to afford primary amines.

Chapter 3 describes the modification of an existing ruthenium catalysed borrowing hydrogen reaction to allow the synthesis of cyclic tertiary amines from diols. This improved system has a lower catalyst loading than previously reported and has been applied to a wide range of substrates.

Chapter 4 focuses on attempts to improve the existing ruthenium catalysed C-N bond forming reactions by reducing the reaction time, reaction temperature or catalyst loading. A comparison of structurally related catalysts already present in the literature, using ionic liquids as an alternative reaction solvent and the application of microwave heating is described.

Chapter 5 details a novel application of benzylic alcohols in a tandem oxidation/C-H activation process. Further exploration of the chemistry resulted in a three-step one pot oxidation/C-H activation/reduction procedure resulting in alkylated benzylic alcohols. This three-step process demonstrates the use of ruthenium in three fundamentally different catalytic processes back to back.

Chapter 6 details the application of nucleophilic aromatic substitution with borrowing hydrogen, hydrogen transfer and a successful tandem isomerisation/substitution. The reaction scope including the nucleophile, reaction solvent, suitable catalyst and electrophile were all evaluated, resulting in specific reaction conditions for a range of para fluoro substituted aromatic vinylic and allylic alcohols.

Date of Award	1 Sept 2011
Original language	English
Awarding Institution	University of Bath
Supervisor	Julian Williams (Supervisor)