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Chemistry and Electricity

Chemistry and Electricity. Zhang Lei 2017/07/29. Chemistry and Electricity. Alessandro Volta. A voltaic pile. Alessandro Volta's discovery, in 1793, that electricity could be produced by placing two dissimilar metals on opposite sides of a moistened paper.

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Chemistry and Electricity

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  1. Chemistry and Electricity Zhang Lei 2017/07/29

  2. Chemistry and Electricity Alessandro Volta A voltaic pile • Alessandro Volta's discovery, in 1793, that electricity could be produced by placing two dissimilar metals on opposite sides of a moistened paper. • In 1800, Nicholson and Carlisle, using Volta's primitive battery as a source, showed that an electric current could decompose water into oxygen and hydrogen.

  3. Electrode Potential Electrode Potential φ= VmetalVsolution Interfacial potential differences are not directly observable. Principle of electroneutrality states that each atom in a stable substance has a charge close to zero.

  4. Galvanic cell

  5. Activity Series of the Metals and Cell Potentials

  6. Standard Hydrogen Electrode When this electrode is operated under standard conditions of 1 atm H2 pressure, 25°C, and pH = 0, it becomes the standard hydrogen electrode, sometimes abbreviated SHE.

  7. Standard Reduction Potentials

  8. Electrolytic cell Electrolysis refers to the decomposition of a substance by an electric current. IR ⎯⎯电解池内阻引起的电压降 ΔΕ不可逆 ⎯⎯由于电极极化作用所致

  9. Electrodes and Electrode Reactions • Electrochemistry is the study of reactions in which charged particles (ions or electrons) cross the interface between two phases of matter, typically a metallic phase (the electrode) and a conductive solution, or electrolyte.  • An electrode reaction refers to the net oxidation or reduction process that takes place at an electrode. This reaction may take place in a single electron-transfer step, or as a succession of two or more steps. The substances that receive and lose electrons are called the electroactive species.

  10. Organic Electrochemistry • Use of electrical current through a reaction to activateorganic molecules through the addition or removal of electrons Fry, A. Electochem. Soc. Interface 2009, 28-33.

  11. Electrochemical Cell Undivided Divided • Simplest design • Must ensure compoundcompatibility • Use of protic solvents aidsin reaction mediation • More complex (andexpensive) • Avoids issue ofcompound compatibility

  12. Oxidation Reduction

  13. Early Beginning

  14. Organic Electrochemistry Why? • Reaction economy • Direct control of electron energy via over potential • Electrons/protons are (typically) sole reagents • Synthetic utility • Umpolung chemistry • High, typically predictable, tolerance of functionalgroups Frontana-Uribe, B.A. et al Green Chem. 2010, 12, 2099-2119

  15. Anodic Oxidation • Removal of electron from substrate • Coupling of electron-rich olefins Wright, D. L., et al Chem. Soc. Rev. 2006, 35, 605-621

  16. Anodic Oxidation • Sequential Horner-Emmons-Wadsworth/ Michael reaction strategy Kevin D. Moeller., et al J. Am. Chem. Soc. 2002, 124, 9368-9369

  17. Kolbe Oxidation Schäfer, H. J., et al Tetrahedron Lett. 1988, 29, 2797-2800.

  18. Non-Kolbe Oxidation Shibasaki, M. et al Tetrahedron 1991, 47, 531-540.

  19. Non-Kolbe Oxidation Hudlicky, T. et al J. Am. Chem. Soc. 1997, 119, 7694-7701.

  20. Non-Kolbe Oxidation Proposed mechanism Phil S. Baranet al nature.2016, 553, 77

  21. NHK Reaction • Adaption of Nozaki-Hiyama-Kishi reaction • Sacrificial anode allow for catalytic use of Cr(II) Durandetti, M. et al Org. Lett. 2001, 3, 2073-2076.

  22. Use of Electroauxiliaries (EA) • Electroauxiliaries make the electron-transfer process more favorable.

  23. Principles of Electroauxiliaries (C-Si, C-Sn) • The energy level of a C-Si σ orbital is usually much higher than that of C-H and C-C σ orbitals. σ-n Interactions.

  24. Use of Electroauxiliaries • Introduction of a functional group that promotes electron transfer in a more selective manner • Electroauxiliaries activate organic molecules toward electron transfer and control the fate of thus generated reactive intermediates and then bias the formation of desired products.

  25. Use of Electroauxiliaries • Electroauxiliaries: Regioisomer control

  26. Electroauxiliaries: Selective Oxidation • Use of two different electroauxiliaries Yoshida, J. et al Chem. Lett. 1998, 1011-1012.

  27. Electroauxiliaries: Selective Oxidation • Use of two different electroauxiliaries Yoshida, J. et al Top. Curr. Chem. 1994, 170, 40.

  28. Electroauxiliaries: Cyclization Fluorination • Inclusion of fluorine during cyclization Proposed mechanism Yoshida, J. et al J. Am. Chem. Soc. 1992, 114, 7594-7595.

  29. In Situ Electroauxiliaries

  30. Cationpool • “Cation pool” method for oxidative carbon-carbon bond formation. Yoshida, J. et al J. Am. Chem. Soc. 1999, 121, 9546.

  31. Cationpool • Combinatorial parallel synthesis based on the “cationpool” method. Yoshida, J. et al J. Am. Chem. Soc. 1999, 121, 9546.

  32. Cationpool

  33. Cationpool:C-H Cross-coupling Yoshida, J. et al Angew. Chem. Int. Ed. 2012, 51, 7259-7262.

  34. StabilizedCation pool:C-H Cross-coupling Application Yoshida, J. et al J. Am. Chem. Soc., 2016, 138, 8400–8403

  35. C-N Cross-coupling Proposed mechanism Yoshida, J. et al J. Am. Chem. Soc. 2013, 135, 5000-5003.

  36. C-N Cross-coupling Yoshida, J. et al J. Am. Chem. Soc. 2015, 137, 9816

  37. C-N Cross-coupling Yoshida, J. et al J. Am. Chem. Soc. 2015, 137, 9816

  38. Electrochemical AreneAminationby Yoshida Yoshida, J. et al J. Am. Chem. Soc. 2015, 137, 9816 Yoshida, J. et al J. Am. Chem. Soc. 2013, 135, 5000-5003. Yoshida, J. et al J. Am. Chem. Soc. 2014, 136, 4496-4499.

  39. Synthesis of Pentacyclosqualeneand β-onoceradiene Corey, E. J.et al J. Am. Chem. Soc. 1959, 81, 1739-1743

  40. Synthesis of diazonamide-inspired drug development candidate DZ-2384 Patrick G. Harran. et al Angew. Chem. Int. Ed. 2015, 54, 4818 –4822

  41. Synthesis of Alliacol A Moeller, K. D. et al J. Am. Chem. Soc. 2003, 125, 36-37

  42. Synthesis of Alliacol A At least two mechanisms for key anode oxidation step Wright, D. L. et al J. Org. Chem. 2004, 69, 3726-3734.

  43. Substrates subjected to cyclic voltammetric(CV) analysis Wright, D. L. et al J. Org. Chem. 2004, 69, 3726-3734.

  44. Anodic Oxidation: Mediation of Pd • Wacker oxidation of terminal alkenes Kevin D. Moeller., et al J. Am. Chem. Soc. 2004, 126, 6212-6213

  45. Anodic Oxidation: Mediation of Pd

  46. Molecular libraries • Preparation of an addressable molecular library on a microelectrode array CombiMatrix Corporation. Kevin D. Moeller., et al J. Am. Chem. Soc.2006, 128, 70-71

  47. Molecular libraries Kevin D. Moeller., et al J. Am. Chem. Soc. 2006, 128, 70-71

  48. Addressable libraries Yoshida, J. et al Angew. Chem. Int. Ed. 2010, 49, 3720 – 3722

  49. Addressable libraries Kevin D. Moeller., et al J. Am. Chem. Soc. 2004, 126, 6212-6213

  50. Cathodic reduction: Mediation of Pd • Electrochemically Assisted Heck Reactions Kevin D. Moeller., et al J. Am. Chem. Soc. 2005, 127, 1392-1393

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