Presenter: Colin Barnett Barnett
Authors: Colin Barnett
Faculty Advisor: Nathan Werner
Institution: Southern Utah University
Molecular geometry, the spatial orientation of atoms, plays a vital role in the overall stability and reactivity of a molecule. Stilbene compounds are an example of molecules with defined molecular geometry. They contain a central ethylene moiety with two aromatic groups on the same side of the carbon-carbon double bond (cis) or flanking opposite sides of the carbon-carbon double bond (trans) configuration. A review of literature reveals the challenge of synthesizing pure trans-stilbene compounds. In addition, these important compounds show a variety of biological activity that is affected by the molecular geometry of the ethylene moiety. The effect of electronic variation on the organometallic donor (styrenylboronic acid pinacol ester) on the yield and geometrical selectivity on the Suzuki-Miyaura cross-coupling reaction was studied. Derivatives with five different substituents on the organometallic donor were synthesized by 9-borobicyclononane (9-BBN) catalyzed hydroboration reaction of an alkyne with pinacol borane. Optimization of the phosphine ligand was critical to obtain the trans-stilbene products in high yield and geometrical purity. This work will improve the versatility of this method in the organic synthesis of medicines, materials, and fine chemicals.