Studies On The Synthesis, Application Of Fuctionalized Diazoacetoacetates

In this dissertation, a general Lewis-acid catalyzed carbocationic coupling reaction of enoldiazo compounds to afford functionalized diazoacetoacetates was introduced as well as the utility of enoldiazo coupling reactions to prepare complex organodiazo templates was demonstrated; Besides that, a facile, efficient and highly stereoselecive desymmetrization of 8,δ-diaryl diazoacetoacetates has been developed by using chiral dirhodium carboxylate catalysts. In addition, a method for the deoximation of ketoximes and aldoximes by using catalytic amount of RuCl3 as a promoter for hydrolysis was developed.We have developed a general Lewis-acid catalyzed carbocationic coupling reaction of enoldiazo compounds, including coupling with benzhydryl, allylic and oxonium carbocations to afford functionalized diazoacetoacetates. These couplings facilitate the rapid assembly of complex organodiazo compounds that provide a template for the synthesis of a variety of carbocyclic and heterocyclic ring systems.Based on the previously functionalized diazoacetoacetates, we further demonstrated the utility of enoldiazo coupling reactions to prepare complex organodiazo templates, which are useful for the construction of natural product-like scaffolds. When combined with the array of coupling reactions that have been reported for enoldiazo compounds, the application these reagents presents a unique opportunity to apply DOS-type strategies to rapidly access large and diverse libraries of medicinally interesting compounds.Besides that, a facile, efficient and highly stereoselecive desymmetrization of δ.δ-diaryl diazoacetoacetates has been developed by using chiral dirhodium carboxylate catalysts. This study provides a two-step process for the formation of 4-aryltetralones in high optical purity, and with aryltetrahydroazulene enantioselectivities up to 99% ee. The esymmetrization methodology has overcome the barrier for high enantiocontrol that is associated with acceptor-acceptor diazoacetoacetates and the Buchner reaction. Furthermore, the utility of P-tetralones formed by this methodology to prepare precursors to 4-P-PDOT has been demonstrated.In addition, we have developed a simple efficient and general method for the deoximation of ketoximes and aldoximes, using catalytic amount of RuCl3 as a promoter for hydrolysis. To the best of our knowledge, the protocol presented here represents the first example of hydrolytic deoximation with catalytic amount of catalyst-RuCl3. Moreover, this strategy appears to be advantageous in terms of chemical yield, variety of substrates and reaction conditions.