Br？nsted Acid of Keggin Type Polyoxometalate Catalyzed Pinacol Rearrangement

Keggin type polyoxometalates K4[a-SiW12O40] was synthesized and transformed to H4[a-SiW12O40]. Both catalysts have been used for pinacol rearrangement in toluene at 373 oK. The results showed that reaction of pinacol rearrangement did not proceed using K4[a-SiW12O40] as catalyst. The extent reac-tion time until 20 h also did not produce pinacolone as main product. By using H4[a-SiW12O40] as cata-lyst at 1 h reaction time gave conversion 100% with formation of pinacolone 72%. The reaction produce 27% of 2,3-dimethyl-1,3-butadiene as byproduct and 99% carbon balance for the reaction. This phe-nomenon indicated the Br？nsted acid is a key role for catalytic reaction of pinacol rearrangement to pinacolone. ？ 2014 BCREC UNDIP. All rights Submitted: 21st January 2014; Revised: 21st April 2014; Accepted: 3rd May 2014 [ How to Cite: Lesbani, A., Mohadi, R., (2014). Br？nsted Acid of Keggin Type Polyoxometalate Catalyzed Pinacol Rearrangement. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (2): 136-141. (doi:10.9767/bcrec.9.2.6074.136-141) ] [ Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.2.6074.136-141