N-Heterocyclic Carbene-Phosphine Iridium Catalyzed Alkylation Reactions and Asymmetric Hydrogenation of Ketones

Sammanfattning: This thesis is focused on hydrogen transfer reactions using N-heterocyclic carbenephosphine iridium catalysts and is divided in two parts. The first part describes the use of achiral N-heterocyclic carbene-phosphine iridium complexes catalyzing the methylation of ketones and alkylation of amides using alcohols as the electrophile. In Chapter 2, the N-heterocyclic carbene-phosphine iridium complexes that have been developed in the Andersson group was employed as catalysts for the methylation of ketones. These reactions were found to take place under mild conditions with low catalyst loading (1.0 mol%) to furnish the desired methylated products in up to 98% isolated yield. The achiral N-heterocyclic carbene-phosphine iridium complexes were also found to catalyze the N-alkylation of amides with alcohols, as presented in Chapter 3. It was discovered that the reactivity of the catalysts was highly dependent on the structure of the catalyst. At optimum reaction conditions, the best catalyst could be used with a wide range of substrates at low catalyst loading (0.5 mol%) to afford the desired product up to 98% isolated yield.The second part of this thesis details the preparation of chiral N-heterocyclic carbenephosphine iridium complexes and their use in the asymmetric hydrogenation of ketones (Chapter 4). These catalysts were successfully used in the asymmetric hydrogenation of ketones at room temperature under base-free conditions and led to full conversion of chiral alcohol products in 30 min with high enantiomeric excess (up to 96%).