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Organic Building Blocks Derived From Carbon Dioxide Nickeisha Stephenson Stahl and Gellman groups October 25 th 2007.

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Presentation on theme: "Organic Building Blocks Derived From Carbon Dioxide Nickeisha Stephenson Stahl and Gellman groups October 25 th 2007."— Presentation transcript:

1 Organic Building Blocks Derived From Carbon Dioxide Nickeisha Stephenson Stahl and Gellman groups October 25 th 2007

2 2 The Carbon Cycle Liu, C-J., Mallison, R.G., Aresta, M., Utilization of Greenhouse gases, ACS Symposium Series, 2003 Since the pre industrial era CO 2 levels have risen from 270 ppm-380 ppm

3 3 Where is our excess CO 2 coming from Liu, C-J., Mallison, R.G., Aresta, M., Utilization of Greenhouse gases, ACS Symposium Series, 2003

4 4 Industrial Sources of Carbon tons of carbon finite resource Atmosphere – tons carbon Carbonates Tons carbon

5 5 Closing the Cycle

6 6 CO 2 usage industrially 120Mt/year CO2 Used in Industry Urea 60Mt/Year Polycarbonate Few kt/ year MeOH 10Mt/year Salicylic Acid 20 kt/ year Inorganic Carbonates ~30 Mt/year Liu, C-J., Mallison, R.G., Aresta, M., Utilization of Greenhouse gases, ACS Symposium Series, 2003

7 7 CO 2 Chemically Transformed Annually 120Mt Large Available Carbon Feedstock Liu, C-J., Mallison, R.G., Aresta, M., Utilization of Greenhouse gases, ACS Symposium Series, 2003

8 8 Carbon Dioxide Thermodynamics CO 2 is carbon in its most oxidized form Liu, C-J., Mallison, R.G., Aresta, M., Utilization of Greenhouse gases, ACS Symposium Series, 2003

9 9 In Other Words In order to make CO 2 into a useful compound, energy needs to be supplied to reduce the oxidized species Sakakura, T. Choi J-C., Yasuda, H.Chem. Rev. 2007, 107,

10 10 MO Diagram CO 2 1.Salahub, D.R. and Russo, N., Metal Ligand Interactions: From atom Clusters, to surfaces, 1991; p

11 11 Some Not So Unfamiliar Reactions Of Carbon Dioxide Liu, C-J., Mallison, R.G., Aresta, M., Utilization of Greenhouse gases, ACS Symposium Series, 2003

12 12 Basic CO 2 Insertion Mechanism

13 13

14 14 Insertion into an M-C Bond

15 15 Relative Rates of Insertion PMe 3 > PPh 3 Increasing the basicity of the phosphine ligand, increases electron density on the metal, allowing for faster CO 2 insertion Kolomnikov, I.S., Gusev, A.O., Belopotapova, Grigoryan, M.Kh., Lysyak, T.V., Struchkov, Yu. T., Volpin, M.E J. Organometallic Chem., 1974, 69, C10-C12

16 16 Me > Ph Decreasing electron withdrawing ability of R group, increases electron density at the metal center, thereby increasing CO 2 insertion Darensbourg, D., Grötsch, G., Wiegreff, P., Rheingold, A, Inorg. Chem., 1987, 26,

17 17 Benzoic Acid and Methyl Benzoate Formation Reaction not catalytic Kolomnikov, I.S., Gusev, A.O., Belopotapova, Grigoryan, M.Kh., Lysyak, T.V., Struchkov, Yu. T., Volpin, M.E J. Organometallic Chem., 1974, 69, C10-C12

18 18 Catalytic Formation of Benzoic Acids Ukai, K., Aoki, M., Takaya, J., Iwasawa, N., J. Am. Chem. Soc. 2006, 128,

19 19 Ukai, K., Aoki, M., Takaya, J., Iwasawa, N., J. Am. Chem. Soc. 2006, 128,

20 20 Insertion Into M-O bonds

21 21 Organic Carbonates Polycarbonate Synthesis Solvent Fuel Additive Carbonylating and Alkylating agent High boiling solvents Reactive intermediates Cosmetics Antifreeze Electronics Optical media Sheeting Water Bottles 2.7 million tons produced annually

22 22 Organic Carbonate Production Dimethyl Carbonate Cyclic Carbonates Polymeric Carbonates Tundo, P., Selva, M. Acc. Chem. Res. 2002, 35, ukuoka, S., Kawamura, M., Komiya, K., Tojo M., Hachiya, H., Hasegawa, K., Aminaka, M., Hirosige O., Fukawa, Konno, S Green Chemistry, 2003, 5,

23 23 Phosgene MAK = maximum allowable concentration in the work place LC 50 = Concentration lethal to kill 50% of a population Used as a chemical weapon during WWI Leitner, W. Angew. Chem. Int. Ed. Engl. 1995, 34,

24 24 Dimethyl Carbonate: Phosgene Substitute But… Tundo, P., Selva, M Acc. Chem. Res. 2002, 35, Choi, J-C., He, L-N., Yasuda, H., Sakaura, T, Green Chemistry, 2002, 4,

25 25 Overcoming Thermodynamics Adding drying agents to remove water - Na(SO 4 ) 4, MgSO 4, dicyclohexylcarbodiimide, PPh 3 and molecular sieves did not help reaction Dehydrating methanol, to eliminate the production of water 88% yield Choi, J-C., He, L-N., Yasuda, H., Sakaura, T, Green Chemistry, 2002, 4,

26 26 Redesigning the experimental set up 46% yield Choi, J-C., He, L-N., Yasuda, H., Sakaura, T, Green Chemistry, 2002, 4,

27 27 Polycarbonates and Cyclic Carbonates From CO 2 and Epoxides

28 28 Heterogeneous Systems Ree. M, Bae, J.Y., Jung, J.H., Shin, T.J J. Polym. Sci. Part A 1999, 37,

29 29 Zinc Glutarate Catalysis Ree, J. Cat 2003, 218, 386 Darensburg, Chem Rev. 2007, 107, 2388

30 30 Salen complexes for polymerization Reaction shows a first order dependence on catalyst Darensbouorg, D.J., Yarbrough, J.C.J. Am. Chem. Soc. 2002, 124,

31 Initiation Propagation

32 32 Cyclic Carbonate Formation Paddock R.L., Nguyen, S.T, J. Am. Chem. Soc. 2001, 123,

33 33 Polycarbonate Produced from CO 2, Industrially

34 34 Insertion into a M-H bond

35 35 Formic Acid ,000 tons of formic acid produced annually - Silage for animal food - Coagulant for latex rubber - Food additive - Tanning and dyeing

36 36 Formic Acid Production Current Industrial Route Alternate Route One Pot Synthesis of Derivatives Leitner, W., Angew Chem. Int. Engl. 1995, 34,

37 37 Unfavorable Thermodynamics Jessop, P.G., Tako, I., Noyori, R., Chem. Rev. 1995, 95,

38 38 Initial Catalytic System TOF = turn over frequency= mol HCOOH/ mol catalyst h -1 HCO 2 H Yield (mol/ mol cat.) Water added (mmol) Hydrolysis rate determining step Inoue, Y., Izumida, H., Sasaki,Y., Hashimoto, H., Chem. Lett., 1976,

39 39 Proposed Mechanism Rate determining step Inoue, Y., Izumida, H., Sasaki,Y., Hashimoto, H., Chem. Lett., 1976,

40 40 Effects Base on Hydrogenation Reaction Base must be capable of deprotonating and stabilizing formic acid Munshi, P., Main, A.D., Linehan, J.C, Tai, C-C., and Jessop, P.G., J. Am. Chem. Soc.,2002, 124,

41 41 Effects of Protic Source Munshi, P., Main, A.D., Linehan, J.C, Tai, C-C., and Jessop, P.G., J. Am. Chem. Soc.,2002, 124,

42 42 Putting the Pieces Together pKa HCO 2 H yield (mol per mol NR 3 ) Effective alcohols have aqueous pKas below that of the protonated amine Alcohols may help to facilitate CO 2 insertion Munshi, P., Main, A.D., Linehan, J.C, Tai, C-C., and Jessop, P.G., J. Am. Chem. Soc.,2002, 124,

43 43 Hydrogenation of CO 2 Despite the unfavorable thermodynamics for the hydrogenation of CO 2 addition of an appropriate base and alcohol helps to over come these barriers Another strategy in bringing about CO 2 hydrogenation would be to carry out the reaction in supercritical CO 2

44 44 Supercritical CO 2 Critical point (C) CO 2 Temperature = 31.0°C Pressure = 73.75bar

45 45 Increased Rates Observed in ScCO 2 Jessop, P.G., Tako, I., Noyori, R. Nature, 1994, 368, Jessop, P.G., Hsiao, Y., Ikariya, T., Noyori, R., J. Am. Chem. Soc., 1996, 118, Munshi, P., Main, A.D., Linehan, J.C, Tai, C-C., and Jessop, P.G., J. Am. Chem. Soc., 124,

46 46 Methyl Formate TOF = 68 h -1

47 47 Formamides and Alkyl Formates

48 48 Formamides Addition of amine to the formic acid reaction results in the formation of formamides Jessop, P.G., Hsiao, Y., Ikariya, T., Noyori, R., J. Am. Chem. Soc., 1996, 118,

49 49 Conclusions Carbon dioxide is kinetic and thermodynamically stable, however, it can be activated in the presence of strong nucleophiles and metal complexes with high electron density at the metal center Insertion into a metal- element bond (M-C, M-H and M-O) leads to the formation of new compounds that can react further to produce more interesting compounds The field of carbon dioxide utilization is still in its infancy, but it needs to grow up in order to alleviate our dependence on fossil fuels. This can only come with further research and more academic interests in this field.

50 50 Future directions Mechanistic studies to better understand the role of additives and the elimination of carboxylate and catalyst regeneration in order to build better catalysts It would be ideal to carry out these reactions efficiently under 1 atm of CO 2 Development of new reactions Coupling coordination chemistry with electrochemistry

51 51 Acknowledgements Prof. Stahl and Prof Gellman Stahl and Gellman Groups Practice Talk Attendees Brian Popp Avery Watkins Chris Scarborough Holly Haase Amanda King Olivia Johnson Lauren Huffman Jessica Menke Richard McDonald Tulay Atesin Nattawan Decharin Xuan Ye Special thanks to Lauren Huffman and Jason Leonard, for keeping me sane


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