Three-Component Carbenylative Coupling Reaction Involving Palladium Alkylidene Intermediates
- Author(s): Nguyen, Thi Anh;
- Advisor(s): Van Vranken, David L.;
- et al.
In Chapter 1, an overview of the literature of palladium-catalyzed carbenylative coupling reaction was reviewed. Palladium alkylidene intermeditates derived from N-tosylhydrazones and diazo compounds were used in the carbenylative reactions with facile β-hydride elimination, which erased the stereogenic center formed during carbene insertion. The review also covered palladium-catalyzed carbenylative coupling reaction without β-hydride elimination.
In Chapter 2, a palladium-catalyzed three-component intermolecular carbenylative amination and alkylation reaction of vinyl iodides, N-tosylhydrazones and nucleophiles were successfully carried out to yield products resulting from nucleophilic attack on the least hindered side of the η3-allylpalladium complexes. With the optimized reaction conditions, a variety of N-tosylhydrazones and nucleophiles were explored. The reaction works well with cyclic secondary amines and stabilized enolates and moderately with primary amines. A variety of alkyl N-tosylhydrazones have been demonstrated to work with the reaction conditions as well. Good yields were obtained under conditions that minimized the palladium-catalyzed ionization of allylic amines and addition of metalated hydrazones to η3-allylpalladium complexes.
In Chapter 3, vinyl iodides, carbon or nitrogen based nucleophiles and trimethylsilyldiazomethane (TMSD) were utilized to form vinylsilanes via palladium-catalyzed carbenylative cross-coupling reactions. These vinylsilanes were then subjected to iododesilylation conditions to generate new vinyl iodides capable of undergoing a second palladium-catalyzed cross-coupling reaction. This two-step process could be used iteratively to form new C-C and C-N bonds that quickly increased molecular complexity.