In recent years, chemists have increasingly focused on environment friendly approaches to organic chemistry. By practicing Green Chemistry, chemists are attempting to reduce the use of hazardous materials and minimize waste. Green chemistry, which involves the design and some times redesign of chemical syntheses that are more environmentally friendly, attempts to lower risk by using inherently less toxic or non-toxic reagents.
The goal of this research was to (1) investigate the use of bismuth triflate as a catalyst for resorcinarene formation as well as the synthesis of homoallyl ethers and (2) to investigate the utility of ionic liquids as solvents for a one-pot synthesis of homoallyl ethers. Bismuth triflate is an attractive Lewis acid catalyst because it is relatively non-toxic, is inexpensive and is easy to handle. Bismuth triflate (5 mol %) has been shown to catalyze the condensation of resorcinol with various aldehydes to form the corresponding resorcinarene in good yield. This method is attractive because of the fast reaction times and the use of a non-toxic catalyst. Studies were also conducted to better understand the mechanism of resorcinarene formation as well as the conformational changes that these compounds can undergo.
A bismuth triflate catalyzed one-pot synthesis of homoallyl ethers from the corresponding aldehydes has also been developed. This method allows the direct conversion of an aldehyde to the corresponding homoallyl ether without the need for isolation and purification of the acetal intermediate.
Another area of focus for the Green Chemistry movement is the replacement of volatile organic solvents. Most volatile organic compounds (VOCs) contribute to the formation of ground-level ozone. Ozone is a very irritating pollutant that produces symptoms like coughing and reduced lung function. Therefore, the reduction of these vapors in the lower atmosphere is desired. Ionic liquids seem to be the most promising replacement for VOCs in organic chemistry. Ionic liquids are defined as ionic compounds that are liquids at or near room temperature. Due to their ionic nature, these compounds have practically zero-vapor pressure and therefore they do not pose any respiratory problems. The utility of ionic liquids as solvents has been explored in the one-pot synthesis of homoallyl ethers.
Smith '04, Russell C., "Environment Friendly Organic Synthesis" (2004). Honors Projects. 2.