Synthesis and chemistry of aromatic heterocycles involving sulfur and boron.

This dissertation describes the study of novel aromatic heterocycles compared to their carbon analogs. In Part A, transition-metal complexes of anionic boron heterocycles were synthesized as potential homogeneous olefin polymerization catalysts. Two novel ansa-zirconium complexes of boratabenzene bridged by 1 or 2 carbons through boron were prepared: [ortho-phenylenebis(1-boratabenzene)]zirconium dichloride and [isobutylidenebis(1-boratabenzene)]zirconium dichloride. The structure of [isobutylidenebis(1-boratabenzene)]zirconium dichloride was determined by X-ray crystallography. The first synthesis of lithium 1,2-benzothiaborolide is described and the heterocycle was shown to be an electronic analog of indenyl. Lithium 1,2-benzothiaborolide was converted to Cp*Ru and Cp*ZrCl2 complexes, in which the ligand acts as a pi-donor to the metals. In Part B, the first preparation of 1,2-thiarsole is described. The structural and spectroscopic data are consistent with 1,2-thiarsole being an aromatic compound. 1,2-Thiarsole was used to prepare Mn(CO)3 and Cr(CO) 3 complexes. The first synthesis of 1,2-benzothiaphosphole is described. The novel heterocycle could not be isolated but was detected spectroscopically in dilute solution.PhDOrganic chemistryPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/130499/2/3042164.pd