Synthesis of Heterocycles and Carbocycles Through Tandem and Domino Palladium-catalyzed Reactions

We have described two important classes of palladium-catalyzed reactions for the synthesis of heterocycles and carbocycles: tandem Pd-catalyzed reactions of gem-dibromoolefins and domino Pd-catalyzed reactions via an ortho C−H functionalization. Chapter 1 describes the tandem Pd-catalyzed reaction of gem-dibromoolefins via an intramolecular direct arylation and an intermolecular Suzuki-Miyaura cross-coupling. A number of aromatic carbocycles were synthesized by this method. Chapter 2 describes the tandem Pd-catalyzed reactions of β,β-dibromoenamides via an intramolecular C−O bond formation and an intermolecular Suzuki-Miyaura cross-coupling. Depending on the substituent on the nitrogen of β,β-dibromoenamides, either aromatic heterocycles or acyclic compounds can be synthesized. Chapter 3 and 4 describe the domino Pd-catalyzed reactions via an ortho C−H functionalization of aryl iodides. 2-Pyrrole substituted phenyl iodides were coupled with alkyl bromides in the presence of norbornene to provide aromatic tetracyclic compounds through three C−C bond formations (Chapter 3). However, the reaction between 2-methyl substituted phenyl iodides and the alkyl bromides in the presence of norbornene provided tetrasubstituted helical alkenes with the norbornene incorporated in the final product through four C−C bond formations (chapter 4). In Chapter 5, detailed mechanistic studies including kinetic and NMR studies were described for the regioselective C−H functionalization of 2-pyrrole substituted phenyl iodides. The studies provided advanced and important understanding of the mechanism, and a rationale for the high regioselectivity.Ph