Since the Pollution Prevention Act was passed in 1990, synthetic organic chemists have focused on the use of environmentally friendly reagents. Often, many synthetic labs use metal catalysts (compounds containing Hg, Ni, Pb, & Sn) that are toxic to or have detrimental effects on the environment. Unlike many heavy metal compounds, bismuth and its compounds have been found to be relatively non-toxic and environmentally friendly. Due to poor shielding of the nucleus by the f electrons bismuth compounds have been shown to be efficient Lewis acid catalysts for many reactions.
The goal of this project to utilize bismuth compounds, specifically bismuth(III) iodide, as catalysts for the deprotection of acetals in water. Water is an attractive solvent because it is inexpensive, non-toxic, and non-flammable. The deprotections of cyclic and acyclic acetals and ketals were carried out in good yields using catalytic amounts of bismuth(III) iodide. Furthermore, it has been observed that these reactions exhibit chemoselectivity, for e.g. an acetal can be selectively cleaved in the presence of a TBDMS (tert-butyldimethyl silyl) group.
Bailey '07, Aaron D., "Green Chemistry Using Bismuth Salts Bismuth (III) Iodide Catalyzed Deprotection of Acetals and Ketals in H2O" (2007). Honors Projects. Paper 6.