Organocatalytic Domino Reactions

Sammanfattning: Organocatalyzed reactions involving activation strategies of ketones and aldehydes are important processes in organic chemistry. These activation strategies serve as a versatile platform for the construction of several domino reactions. This thesis describes the development of six new asymmetric or-ganocatalyzed domino reactions for the enantioselective formation of carbo-cycles or heterocycles. The domino reactions are based on two major activation pathways the domino “iminium-enamine” and the domino “enamine-iminium”. Making use of the domino “iminium-enamine” reaction, 2H-1-benzopyrans, 2H-1-benzothiopyrans and 1,2-dihydroquinolines and cyclopropanes can be obtained in high yields and excellent ee´s. Via the amine-catalyzed domino “enamine-iminium” reaction the synthesis of aza-Diels-Alder and Diels-Alder products can be achieved with high ee´s and yields. Moreover, a mechanistic model is proposed for each reaction that enables the stereochemical outcome of the reaction to be predicted.