Development of chiral 1,5-diaza-cis-decalin ligands for asymmetric syntheses, Enantioselective oxidative biaryl coupling reactions, [and] Synthetic studies toward perylenequinone natural products

The work described in this dissertation encompasses three major areas of research. The research started with the development of chiral 1,5-diaza- cis-decalin as novel ligand scaffold for asymmetric synthesis. The chiral ligand 20 was successfully synthesized in a concise manner and a number of derivatives have been prepared conveniently. Complexation study showed 1,5-diaza-cis-decalin ligand could form stable bidentate metal complexes. Derivatives of chiral 1,5-diaza-cis-decalin such as 22 provide moderate enantioselectivity in asymmetric lithiation-substitution reactions.*; The second research area began with the discovery of a highly enantioselective oxidative biaryl coupling reaction of 61 leading to chiral binaphthalene 62 using copper complexes of chiral 1,5-diaza-cis-decalin. A number of highly functionalized chiral 3,3′-disubstituted BINOL ligands were synthesized using this method.*; Studies of the mechanism have revealed that the asymmetric induction is established in the C-C bond forming step. A mild nonlinear effect which is suppressed in the presence of a coordinating agent has been ascribed to aggregation of the catalytic precursor. Kinetic studies reveal saturation behavior for the substrate and first order in behavior for the catalyst. Under saturation conditions, the rate-determining step appears to involve substrate oxidation.; The third research area involves the asymmetric synthesis of perylenequinone natural product precursors. A facile biomimetic approach was proposed featuring an asymmetric biaryl coupling reaction. This novel approach was designed to assemble the stereochemical elements of this class of interesting compounds efficiently.; Chiral 1,5-diaza-cis-decalin copper-complexes catalyzed enantioselective biaryl coupling reactions have been successfully utilized in the synthesis of highly functionalized chiral biaryls such as 188 . The steric and electronic features of the multifunctional substrates required to achieve highly selective and efficient biaryl coupling have been delineated. In a model study toward the perylenequinone structure, a precursor, 198, has been prepared in 9 steps in an overall yield of 22%.