Determination of Hammett’s Sigma Values for Common Boryl-Substituted Compounds

Mary Kate Bielinski, Dr. Jonathan Dannatt, Department of Chemistry, University of Dallas, Irving, TX, 75062

The carbon-boron bond is an extremely versatile bond. The development of the Suzuki cross-coupling reaction, which involves boron chemistry, allowed for revolutionary carbon-carbon bond formation. This reaction continues to be widely used in the synthesis of medicinal products. Given this synthetic utility, physical characteristics of boryl substituents are of interest. This includes Hammett sigma values, which quantify the effect of substituents on reactivity. These values are derived from acid-dissociation constants obtained through acid-base titrations. In this research, the first steps were taken to find these sigma values by developing methods to synthesize and purify molecules containing common boryl substituents, including B(OH)2, BF3K, Bcat, and Bdan. Dean-Stark extraction was found to be a favorable method to drive the conversion of the starting materials forward, and boiling acetone filtrations was an effective method for purification of some compounds. Techniques including Thin Layer Chromatography and NMR spectroscopy were used to monitor the progress of reactions and the purity of the products.

Additional Abstract Information

Presenter: Mary Bielinski

Institution: Dallas Christian College

Type: Poster

Subject: Chemistry

Status: Approved

Time and Location

Session: Poster 4
Date/Time: Tue 11:00am-12:00pm
Session Number: 3585