Ishtiaq Hussain

• Organocatalysis is a relatively new field that focuses on using sub-stoichiometric quantities of small organic molecules to furnish advanced building blocks of medicinal value. In comparison to enzymes and metal catalaysis, organocatalysis at times offer competitive solutions regarding enantioselectivity, diastereoselectivity and yield. Amine based organocatalysts are the most studied organocatalysts and are used for a number of asymmetric organic reactions, typical are Michael and aldol reactions. Over the last 16 years a large variety of acyclic and cyclic ketone substrates, were reported for asymmetric aldol reactions but so far very limited examples are available for diketone substrates in aldol chemistry. Site-selective aldolization of non-hindered diketone substrates using organocatalysts represents a significant chemical challenge. In order to pursue this challenge I synthesized different 4-substituted cyclohexanone to test this concept. The outcome of a site-selective diketone reaction is that one of the two diketone carbonyl moieties is selectively targeted. During this research with 4-substituted cyclohexanones this means that I was able to functionalize the cyclohexanone carbonyl moiety selectively over the ketone carbonyl moiety. This thesis focuses on my progress towards simultaneous site-, chemo-, regio-, diastereo-, and enantiolselective aldol reactions of these diketones.