Palladium-Catalyzed Cyclization For The Construction Of Oxoindoles And Planar Chiral Compounds

This thesis could be devided into two parts.Chapter one:Tosylhydrazones can be used as precursors for diazo compounds in Pd-catalyzed tandem Heck and alkenylation reaction. Diazo compounds have broad applications in organic synthesis, however, the studies on the unstable diazo compounds without stabilization of electron-withdrawing groups in the a-position are limited because of the inconvenient preparation and handling of diazo compounds One possible way to solve this problem is the use of in-situ generated of diazo compounds from stabe precursors. We have developed a palladium-catalyzed Heck-type cascade reaction of organic halides with N-tosyl hydrazones in the presence of5mol%Pd(OAc)2,15mol%of PPh3and3.0equiv LiO’Bu. The reaction gave the expected product in mild conditions, short reaction time and high yields. This method provided a new route to the divergent synthesis of functionalized alkenes and extended the broad utility of N-tosyl hydrazones.Chapter two:Ferrocene is a special kind of metal complexes with a sandwich structure and unusual stability relatively. Ferrocenes with a Cp ring having two different substituents are planar chiral molecules. Nowadays ferrocene have become one of the most successful scaffolds for ligands and catalysts in the area of asymmetric catalysis. Metal-catalyzed asymmetric synthesis of planar chiral molecules attracted extensive attention in recent years. We have studied a palladium-catalyzed intramolecular asymmetric Cp-H functionalization/cyclization reaction to construct planar chiral quinilinoferrocenes. Under the conditions of Pd(OAc)2/(R,Sa)-O-PIMAP and Cs2CO3the cyclization reaction of2-halophenyl ferrocenecarboxylic amides can be performed with high yields and moderate to good enantioselecty. These substrates showed significant different reactivity in comparison with our previous results, and a new catalytic system, Pd(OAc)2/(R,Sa)-O-PINAP, was developed to enantioselectively synthesize the planar chiral quinilinoferrocenes. The reaction provided an efficient way for the construction of planar chiral compounds with new skeletons.