Carboxylation of Aromatics by CO2 under “Si/Al Based Frustrated Lewis Pairs” Catalytic System


Carboxylation of aromatics by CO2 to generate corresponding carboxylic acids is recently providing a novel approach to utilize the green gas CO2, in which the activation of CO2 is the key procedure. Among the many catalytic systems employed in the carboxylation, the concept of “Frustrated Lewis Pairs” (FLPs) was scarcely mentioned, which perform excellently in activating small molecules like CO2. The FLPs are combinations of Lewis acids and Lewis bases which failed to form adducts due to their bulky steric congestion. In this paper, we first attempted various Si/Al Based FLPs to catalyze the carboxylation of aromatics through the activation of CO2, and a good yield of 62% - 97% was obtained. The reaction mechanism was proposed, involving the activation of CO2 mainly contributed by AlCl3 in cooperation with organosilane, forming an intermediate consisting of CO2, AlCl3, and R4Si, as well as the subsequent electrophilic attack to aromatics, thus to promote the carboxylation reaction.

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Gu, M. and Cheng, Z. (2015) Carboxylation of Aromatics by CO2 under “Si/Al Based Frustrated Lewis Pairs” Catalytic System. Journal of Materials Science and Chemical Engineering, 3, 103-108. doi: 10.4236/msce.2015.31015.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Arakawa, H., Aresta, M., Armor, J.N., Barteau, M.A., Beckman, E.J., Bell, A.T., et al. (2001) Catalysis Research of Relevance to Carbon Management: Progress, Challenges, and Opportunities. Chemical Reviews, 101, 953-996.
[2] Olah, G.A., T?r?k, B., Joschek, J.P., Bucsi, I., Esteves, P.M., Rasul, G. and Surya, P.G. (2002) Efficient Chemoselective Carboxylation of Aromatics to Arylcarboxylic Acids with a Superelec-trophilically Activated Carbon Dioxide- Al2Cl6/Al System. Journal of the American Chemical Society, 124, 11379-11391.
[3] Munshi, P. and Beckman, E.J. (2009) Effect of Incubation of CO2 and Lewis Acid on the Generation of Toluic Acid from Toluene and CO2. Industrial & Engineering Chemistry Research, 48, 1059-1062.
[4] Sarve, A.N., Ganeshpure, P.A. and Munshi, P. (2012) Carboxylation of To-luene by CO2 Generating p-Toluic Acid: A Kinetic Look. Industrial & Engineering Chemistry Research, 51, 5174-5180.
[5] Nemoto, K., Yoshida, H., Suzuki, Y., Morohashi, N. and Hattori, T. (2006) Beneficial Effect of TMSCl in the Lewis Acid-Mediated Carboxylation of Aromatic Compounds with Carbon Dioxide. Chemistry Letters, 35, 820-821.
[6] Nemoto, K., Yoshida, H., Egusa, N., Morohashi, N. and Hattori, T. (2010) Direct Carboxylation of Arenes and Halobenzenes with CO2 by the Combined Use of AlBr3 and R3SiCl. The Journal of Organic Chemistry, 75, 7855-7862.
[7] Stephan, D.W. (2013) Discovery of Frustrated Lewis Pairs: Intermolecular FLPs for Activation of Small Molecules. Topics in Current Chemistry, 332, 1-44.
[8] Welch, G.C., San Juan, R.R., Masuda, J.D. and Stephan, D.W. (2006) Reversible, Metal-Free Hydrogen Activation. Science, 314, 1124-1126.
[9] Stephan, D.W. (2008) Frustrated Lewis pairs: a Concept for New Reactivity and Catalysis. Org. Biomol. Chem., No. 6, 1535-1539.
[10] Stephan, D.W. (2010) Activation of Dihydrogen by Non-Metal Systems. Chem. Comm., No. 46, 8526-8533.
[11] Erker, G. (2011) Organo-metallic Frustrated Lewis Pair Chemistry. Dalton Trans., No. 40, 7475-7483.
[12] Ashley, A.E., Thompson, A.L. and O’Hare, D. (2009) Non-Metal-Mediated Homogeneous Hydrogenation of CO2 to CH3OH. Angew Chem. Int. Ed, 48, 9839-9843.
[13] Berkefeld, A., Piers, W.E. and Parvez, M. (2010) Tandem Frustrated Lewis Pair/tris(pentafluorophenyl)borane-catalyzed Deoxygenative Hydrosilylation of Carbon Dioxide. Journal of the American Chemical Society, 132, 10660-10661.
[14] Appelt, C., Westenberg, H., Bertini, F., Ehlers, A.W., Slootweg, J.C. and Lammertsma, K. (2011) Geminal Phosphorus/Aluminum-Based Frustrated Lewis Pairs: C-H Versus C-C Activation and CO2 Fixation. Angewandte Chemie, 50, 4011-4014.
[15] Peuser, I., Neu, R.C., Zhao, X., Ulrich, M., Schirmer, B., Tannert, J.A., et al. (2011) CO2 and Formate Complexes of Phosphine/Borane Frustrated Lewis Pairs. Chemistry—A European Journal, 17, 9640-9650.
[16] Andrew, E., Ashley, A.E. and O’Hare, D. (2013) FLP-Mediated Activations and Reductions of CO2 and CO. Top Curr. Chem., 334, 191-218.
[17] Momming, C.M., Otten, E., Kehr, G., Frohlich, R., Grimme, S., Stephan, D.W. and Erker, G. (2009) Reversible Metal- Free Carbon Dioxide Binding by Frustrated Lewis Pairs. Angewandte Chemie International Edition, 48, 6643-6646.

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