Transition Metal-Catalyzed C-C And C-N Bond Forming Reactions

This thesis is composed of the following four chapters. Chapter 1:Pd(Ⅱ)-catalyzed Heck arylation for C(sp2)-C(sp2) bonds formation:regio-and stereoselective synthesis of (Z)-β-amido-β-arylacrylatesWe have developed a novel PdCl2(COD)/Ag3PO4 catalytic system for arylation of substituted enamides by aryl iodides to construct C(sp2)-C(sp2) bonds for the first time. Under the condition, a broad range of (Z)-β-amido-β-arylacrylates are successfully prepared in a highly efficient manner with excellent yield, remarkable regio-and stereoselective. Chapter 2:Palladium-catalyzed arylation of unactivated C(sp3)-H bonds by (diacetoxyiodo)arenes for the formation of C(sp3)-C(sp2) bondsWe have developed PdCl2(CH3CN)2-catalyzed Cs2CO3-promoted arylation of unactivated C(sp3)-H bonds for the formation of C(sp3)-C(sp2) bonds using (diacetoxyiodo)arenes as arylation reagent. This highly efficient arylation method is assisted by Cs2CO3 and avoids the use of expensive silver salt. The synthetic utility of the method is further illustrated in the synthesis of the psychotropic drug phenibut. Furthermore, a detailed mechanism study has been conducted to understand the reaction pathway. Chapter 3:Pd(Ⅱ)-catalyzed intermolecular amination of unactivated C(sp3)-H bonds for the formation of C(sp3)-N bondsWe have developed a Pd(Ⅱ)-catalyzed amination of β-C(sp3)-H bonds of carboxylic acid derivatives using BzO-NR1R2 as amination reagents. This method provides a new way to achieve the challenging intermolecular amination of unactivated C(sp3)-H bonds. This approach produces a variety of unnatural β2-amino carboxylic acid analogues. This new C(sp3)-H amination protocol is demonstrated with broad substrate scope, good functional group tolerance and chemselectivity. It is operated smoothly without use of phosphine ligand or external oxidant. In addition, this reaction is scalable on a gram scale. Chapter 4:Intermolecular amination of unactivated C(sp3)-H bonds with alkylamines: formation of C(sp3)-N bonds via copper-mediated C(sp3)-H/N-H activation.Direct amination of unactivated C(sp3)-H bonds with alkylamines is an ideal yet undeveloped method to construct C(sp3)-N bonds, since it avoids the use of the commonly-employed O-benzoyl hydroxylalkylamines as aminating reagent, which are normally prepared from alkylamines through hazardous oxidative steps. We have successfully developed the first example of intermolecular amination of unactivated C(sp3)-H bonds with alkylamines as aminating reagent. This method is mediated by Cu(OAc)2/02 and generates H2O as byproduct. A variety of unnatural β2,2-amino acid analogues are synthesized by this simple and efficient procedure. This approach offers a solution to the previous unmet challenge of C(sp3)-H activation/C(sp3)-N bond formation.