Trace amount of solid-supported fluoroboric acid (HBF4-SiO2) was found to be an effective catalyst for chemoselective and highly efficient protection of carbonyl compounds and transthioacetalization of O,O- and S,O-acetals under solvent-free conditions. Moreover, the catalyst can be recycled for number of times without significant loss of activity. © 2006 Elsevier B.V. All rights reserved.
Kamble, V. T., Bandgar, B. P., Muley, D. B., & Joshi, N. S. (2007). An expedient and efficient chemoselective protection of carbonyl compounds and transthioacetalization of O,O- and S,O-acetals catalyzed by HBF4-SiO2. Journal of Molecular Catalysis A: Chemical, 268(1–2), 70–75. https://doi.org/10.1016/j.molcata.2006.12.001