"Double-decker silsesquioxane (DDSQ) cages closed with some end cap reagents were found to have degradations uncharacteristic for these cages. This could be blamed on the inefficient synthesis of the dichlorosilanes used as end cap reagents as well as possible degradations caused by side reactions involving trace palladium left over from the synthesis of end cap precursors. Work detailing methods of synthesizing end cap precursors without palladium, as well as evaluating palladium levels through the use of inductively coupled plasma - optical emission spectroscopy (ICP-OES) are disclosed. Germanium is not as toxic as tin, but organometallic reactions involving germanium have been studied far less than tin. While research from our lab has shown that germanium can undergo an unusual coupling reaction with aryl iodides that inverts the stereochemistry, the mechanism is still largely unknown and optimizations are still ongoing. However, we have found that the synthesis of vinyl germanes used in the coupling reaction can be performed "on water," which leads to the possibility of a one-pot process involving hydrogermylation and coupling due to the solvent required for the unique coupling reaction. As previously stated, trialkyltin substrates are quite toxic, especially tributyltin hydride. Since trialkylvinyltin reagents are very useful for the Stille cross-coupling reaction, people have looked for alternative methods for synthesizing those tin reagents in selective and less toxic ways. Our group has shown that using poly(methylhydrosiloxane), or PMHS, as a reducing agent can provide the toxic tributyltin hydride in situ from tributyltin halides for palladium catalyzed hydrostannation. We have found that hydrostannations can be performed with tributyltin fluoride and PMHS to in situ create tributyltin hydride, which when reacted in situ with alkynes affords trialkylvinyltin in isomeric ratios similar to those synthesized using commercial tributyltin hydride in the same hydrostannations. The Suzuki-Miyaura cross-coupling reaction has been used extensively by pharmaceutical companies to create carbon-carbon bonds due to its relative ease and lack of toxic byproducts, compared to other methods such as the Stille cross-coupling. However, pharmaceutical companies would like to avoid the ubiquitous use of haloaromatics in the Suzuki-Miyaura reaction due to possible toxicity concerns in haloaromatics and haloaromatic equivalents, such as tosylates and triflates. Imidazolyl sulfonates have previously been demonstrated to be "green" alternatives to the haloaromatics in Suzuki-Miyaura cross-couplings, so we extended their usage into one-pot processes with iridium catalyzed C-H borylation reactions and created our own imidazolyl sulfonates through similar borylations followed by oxidation with Oxone or photoredox catalysis. Iridium catalyzed C-H borylation has been shown to be directed mostly by sterics, but there are other factors which can change the ratio of regiochemical isomers obtained in a borylation, including solvent, ligand, and possible directing groups on the arene to be borylated. Fluorine, in particular, has both a small size and a large inductive effect that changes the ratios of products. In conjunction with Dow Chemical, we have looked at a cross-section of fluorinated arenes for the ratio of products obtained in C-H borylations in a variety of conditions, changing solvents, temperatures, and ligands to determine the changes in regioisomeric ratios of borylated products."--Pages ii-iii.
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