New organocatalytic methods for C-C and C-O bond formation

TL;DRAbstract

The present dissertation deals with novel carbene catalyzed processes for C–C and C–O bond formation. Chapter 1 covers (chemo- and/or stereo-)selective nucleophilic acylation reactions between aldehydes and carbonyl electrophiles. After a brief introduction (chapter 1.1), a highly enantioselective (homo-)benzoin condensation is described in chapter 1.2. A pyroglutamic acid-derived, bifunctional carbene equipped with a protic, substituent R effectuates good to high yields and excellent ee values of the homocoupling products. The presence of a pentafluorophenyl substituent adjacent to the carbene carbon was demonstrated to be prerequisite to ensure a high catalytic activity.The extension to crossed benzoin-type condensations is presented in chapter 1.3: based on a synergism between a highly reactive catalyst system and substrate control, chemoselective cross condensations between aliphatic and ortho-substituted benzaldehydes were accomplished. Contrary to previous alternative methods, a

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