Degree Granting Department
X. Peter Zhang
Corroles, Cobalt(III) Complex, Epoxidation, N-H Insertion, and Cyclopropanation
A variety of bromocorroles, useful precusors for Pd-based cross coupling, were sucessfully synthesized in moderate to good yields. Chiral corroles were also synthesized through use of chiral amides in the aforementioned cross coupling reactions. Cobalt complexes bearing π-acceptor (CNtBu) and σ-donor (PPh3) ligands were also prepared in excellent yields. In this dissertation, cobalt (III) corrole complexes were applied to three different reaction areas: epoxidation, N-H insertion, and cyclopropanation. Cobalt(III) corroles were found to be efficient catalysts for epoxidation reactions. The epoxidation reactions can be carried out using ethyl phenyldiazoacetate, an acceptor/donor diazo compound, as a carbenoid precusor.The reaction provided highly diastereoselective epoxides. In addition to epoxidation, N-H insertion reactions using cobalt(III) corroles as catalysts smoothly produced the desired products with diverse diazo reagents. The reactions were screened using ethyl phenyldiazoacetate with a selection of anilines and amides. In order to investigate non-ylide intermediate based metal-mediated catalytic reactions, cyclopropanation was conducted using cobalt (III) corroles as catalysts, producing the desired cyclopropyl nitroesters in high yields and with excellent diastereoselectivity under a concerted mechanism. Asymmetric cyclopropanation reactions were carried out using chiral cobalt(III) corrole complexes to generate the enatiomerically pure desired cyclopropanes in moderate yields.
Scholar Commons Citation
Kim, Chung Sik, "Corrole Synthesis and Catalytic Applications Toward Cobalt(III)-Catalyzed Epoxidation, N-H Insertion, and Cyclopropanation" (2010). Graduate Theses and Dissertations.