I. Development of the Aqueous Polyhomologation Reaction for the Synthesis of Linear and Branched Hydrocarbons II. Mechanism of the Organoboron-Catalyzed Polymerization of Ylides. The Role of 1,2-Oxygen Migration

This dissertation includes three research projects on the polyhomologation reaction for the synthesis of carbon backbone polymers. Following an overview of the "traditional" polyhomologation reaction in Chapter 1, Chapter 2 reports the discovery of an aqueous polyhomologation reaction of sulfoxonium salts for the synthesis of polymethylene, a linear hydrocarbon polymer. Chapter 3 describes our efforts to extend the aqueous polyhomologation reaction for the synthesis of functionalized polymethylene. Chapter 4 focuses on the mechanistic investigation of the polyhomologation reaction.;Chapter 1 provides a general review of the "traditional" polyhomologation reaction, an organoboron-mediated living polymerization of ylides in anhydrous hydrocarbon solvents at elevated temperature. The reaction produces linear polymethylene. The carbon backbone is built one carbon at a time. The living nature of the polyhomologation reaction provides access to polymethylene with no branches, controlled molecular weight, low PDI, well-defined topology and composition.;Chapter 2 describes a mild polyhomlogation reaction for the synthesis of perfectly linear polymethylene in aqueous base at/near room temperature under atmospheric pressure. A water-stable trialkylborane serves as the initiator/catalyst, and trimethylsulfoxonium halide salts function as monomer reservoirs. The active monomer, dimethylsulfoxonium methylide, is produced in situ and further reacts with trialkylborane to produce polymethylene.;In Chapter 3, the synthesis of functionalized polymethylene is described. The aqueous copolymerization of trimethylsulfoxonium halides and substituted alkyl (dimethylamino)phenylsulfoxonium tetrafluoroborates produces functionalized polymethylene with a broad branch content range and new contiguous branch patterns. The polymer backbone is constructed one carbon at a time from --CH 2-- and --CHR-- fragments. The opportunity for extensive variation of the substituted monomer precursors and the mild polymerization conditions offers the potential to introduce a wide range of functional groups into polymethylene.;Chapter 4 delves into the mechanism of the "traditional" polyhomologation reaction, specifically to identify possible sources of the PDI erosion of the product during the synthesis of high molecular weight polymethylene. The study establishes that trialkylborane reacts with trace quantities of oxygen to produce borinic esters. The catalytic efficiency of these borinic esters in the polyhomologation reaction differs significantly from trialkylboranes. Their presence renders the reaction no longer a "single-site" catalyzed reaction, resulting in a broadened PDI.