UNIVERSITY OF OKLAHOMA GRADUATE COLLEGE SURVEY OF CATALYST AND REDUCTANT EFFECTS ON OXORHENIUM CATALYZED DEOXYDEHYDRATION OF GLYCOLS A DISSERTATION SUBMITTED TO THE GRADUATE FACULTY in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY By JAMES MICHAEL MCCLAIN II Norman, Oklahoma 2015 SURVEY OF CATALYST AND REDUCTANT EFFECTS ON OXORHENIUM CATALYZED DEOXYDEHYDRATION OF GLYCOLS A DISSERTATION APPROVED FOR THE DEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY BY ______________________________ Dr. Kenneth M. Nicholas, Chair ______________________________ Dr. Robert P. Houser ______________________________ Dr. George Richter-Addo ______________________________ Dr. Robert K. Thomson ______________________________ Dr. Ronald L. Halterman ______________________________ Dr. Lee R. Krumholz © Copyright by JAMES MICHAEL MCCLAIN II 2015 All Rights Reserved. To my parents & sisters for a lifetime of love, support, and faith in my shenanigans, thank you. Acknowledgements I would not have made it to where I am today without the friendship, mentorship, encouragement, and support of countless people. I know I cannot adequately thank everyone responsible for influencing me to develop into the person I am today and I will inevitably leave out many who deserve recognition, to those individuals I apologize and greatly thank you. As a child, while working in my grandpa’s workshop he would always tell me “can’t ain’t a word” anytime I said I couldn’t do one thing or another. At the time I thought, ironically, he was giving me a grammatical lesson, it wasn’t till after his passing and I was older that I truly understood what he was telling me. This has become my general philosophy in life when challenges present themselves; I concede that it occasionally leads me to pursue endeavors off the main track but I owe most of my accomplishments to this stubbornness. Of course, my parents and sisters are responsible for much of whom I am and have been a part of all that I have done. My friends have been a second family and have grown too numerous to thank them all for the good times and support but I am greatly appreciative. I have to mention some of my closest friends, Robert, Anna, Katie, and Camille for years of fun, listening to me complain about trivial things, and the motivation to keep moving forward. Thank you to my teachers and mentors all through my life. Particularly my grade school advanced program instructor Ms. Schaflein for encouraging me to think independently and abstractly. I am grateful to all my research mentors, Dr. Tim Hubin, Dr. Bob Houser, and Dr. Ken Nicholas for all that I learned from them, their inspiration, and individual perspectives. iv Table of Contents Acknowledgements ..................................................................................................... iv Table of Contents ..........................................................................................................v List of Tables .............................................................................................................. ix List of Figures ............................................................................................................. xi Abstract .................................................................................................................... xvii Chapter 1 Biomass, a Renewable Carbon Source ....................................................1 1.1 Dependence on Fossil-Based Resources .......................................................2 1.2 Sustainable Energy and Chemical Feedstocks ..............................................4 1.3 Utilization of Cellulosic Biomass .................................................................5 1.4 Conversions of Biomass Derived Sugars and Polyols ...................................8 1.5 Deoxydehydration (DODH) ....................................................................... 10 Chapter 2 Elemental Reductants in the Deoxydehydration of Polyols ................... 25 2.1 Background and Introduction ..................................................................... 26 2.2 Exploratory Reactions with the Activated Substrate DET ........................... 28 2.3 Aliphatic Glycols ....................................................................................... 29 2.4 Reflux Reactions ........................................................................................ 31 2.5 Electronically Different Substrates ............................................................. 32 2.6 Mass Balance for High Conversion/Moderate Yield Reactions ................... 34 2.7 Discussion ................................................................................................. 41 2.8 Conclusion ................................................................................................. 42 2.9 Experimental .............................................................................................. 43 2.9.1 Reagents .............................................................................................. 43 v 2.9.2 Typical Reaction Conditions ................................................................ 43 2.9.3 Notes on Elemental Metals ................................................................... 44 2.9.4 Instrumentation .................................................................................... 45 2.9.5 Quantification Procedures .................................................................... 45 2.9.6 Standard Reaction ................................................................................ 47 2.9.7 Procedure testing for CO and CO2 ........................................................ 48 Chapter 3 Oxorhenium(V) Catalyzed DODH ....................................................... 50 3.1 Background and Introduction ..................................................................... 51 3.2 Synthesis of Trans-[ReO2py4]Cl (1a) ......................................................... 53 3.3 Establishing Catalytic Activity of [ReO2py4]Cl (1a) for DODH with Glycols and Sodium Sulfite ..................................................................................... 54 3.4 Benzyl Alcohol as Reductant ..................................................................... 61 3.5 Nature of Oxorhenium Catalyst in Reaction/Post-Reaction......................... 64 + 3.6 Investigating the Activity of trans-[ReO2py4] in Additional DODH Reactions ................................................................................................... 65 + 3.7 Elemental Reductants for trans-[ReO2py4] catalyzed DODH. ................... 69 3.8 ReO2(TPP)2I (2) as a DODH Catalyst ........................................................ 70 3.9 Conclusions ............................................................................................... 72 3.10 Experimental .............................................................................................. 73 3.10.1 Reagents .............................................................................................. 73 3.10.2 Instrumentation and Analytical Methods .............................................. 74 3.10.3 Typical DODH Reaction Conditions .................................................... 74 3.10.4 Quantification ...................................................................................... 75 vi 3.10.5 Standard Reaction ................................................................................ 75 3.10.6 Mass Spectrometric Experiment Described in Section 3.5 .................... 76 Chapter 4 Mechanistic Studies of Oxorhenium-Catalyzed DODH ........................ 77 4.1 Background and introduction ..................................................................... 78 4.2 Initial reaction time course experiments ..................................................... 82 4.3 Establishing standard reaction conditions and stoichiometry effects ........... 84 4.4 Substituted pyridine analogs of the type [ReO2(4-X-py)4]PF6 ..................... 90 4.5 Observed effect of added pyridine or triphenylphosphine oxide to the [ReO2py4]PF6/BnOH/1,2-decanediol DODH reaction ................................ 92 4.6 Kinetic isotope effect with singly and doubly benzylic deuterium labeled BnOH ........................................................................................................ 93 4.7 Stoichiometric reactions ............................................................................. 97 4.8 Conclusions ............................................................................................. 105 4.9 Experimental ............................................................................................ 107 4.9.1 Reagents ............................................................................................ 107 4.9.2 Instrumentation .................................................................................. 110 4.9.3 Typical Catalytic DODH Reaction Conditions ................................... 111 4.9.4 Quantification .................................................................................... 111 + 4.9.5 ESI-MS of ethylene glycol/[ReO2py4] ............................................... 112 4.9.6 Rhenium calculations ......................................................................... 113 Chapter 5 Project Summary and Future Directions ............................................. 117 5.1 Project summary .....................................................................................