Abstract BLUE, ELIZABETH DODGE. Synthesis and Reactivity of Copper Complexes Possessing Non-dative Ligands (Under the Direction of Dr. T. Brent Gunnoe). Carbon-nitrogen bonds are prevalent in many areas of chemistry including natural products, pharmaceuticals, conducting polymers, and materials for electronic applications. Late transition metals are often used to catalyze carbon-nitrogen bond-forming reactions with diverse substrates and under relatively mild conditions. Hydroamination and aryl amination catalysis may proceed via Cu(I) amido complexes, and Cu-catalyzed aziridination catalysis may proceed via Cu(III) nitrene intermediates. Detailed investigation of these potential intermediates and reaction mechanisms could further the development of these critical reactions. Besides potential catalytic application, many late transition-metal non- dative complexes possess significant basic and nucleophilic reactivity. Presented herein are the isolation and characterization of a number of new copper(I) halide complexes and the first two examples of monomeric copper(I) amido complexes, (dtbpe)Cu(NHPh) and (IPr)Cu(NHPh). These Cu(I) anilido complexes have been shown to be more nucleophilic than a related Ru(II) anilido complex in reactivity studies with bromoethane, and reveal increasing nucleophilicity in the order (SIPr)Cu(NHPh) < (IPr)Cu(NHPh) < (IMes)Cu(NHPh) < (dtbpe)Cu(NHPh). (IPr)Cu(NHPh) is thermodynamically favored over (IPr)Cu(Ph)/NH2Ph or [(IPr)Cu(μ-H)]2/NH2Ph, respectively. Computational studies are consistent with the observed reactivity and indicate strong Cu-N bonds with nucleophilic amido nitrogen. The two amido complexes (dtbpe)Cu(NHPh) and (IPr)Cu(NHPh) are active for hydroamination catalysis of electron-withdrawing olefins, and (IPr)Cu(NHPh) is observed to undergo stoichiometric and catalytic aryl amination with PhI and PhOTf. The mechanism and analysis of the scope of these reactions will continue to be investigated. Reactions towards synthesis of a Cu(III) nitrene complex with LCu(I) (L = dtbpe, NN, or IPr) complexes have largely resulted in decomposition to amine products and Cu(II) species. However, reactions with (NN)Cu(NCMe) complexes and phenyl azide did result in formation of a non-isolable transient species which may be either a Cu(III) nitrene or a Cu(II) species. Reaction of (IPr)Cu(OTf) with strong acid yields a protonated carbene ligand indicated by a downfield peak which binds η2 through the imidazolium phenyl ring of the amido complex. The synthesis and reactivity studies described herein have provided a foundation for continued fundamental studies of copper(I) non-dative species and mechanistic and applied C-X (X = N, O, or S) bond-forming catalytic investigations. Synthesis and Reactivity of Copper Complexes Possessing Non-dative Ligands by Elizabeth D. Blue A dissertation submitted to the Graduate Faculty of North Carolina State University In partial fulfillment of the Requirements for the degree of Doctor of Philosophy CHEMISTRY Raleigh, NC 2006 Approved by: _______________ _______________ T. Brent Gunnoe James D. Martin Chair of Advisory Committee _______________ ________________ Christian Melander David A. Shultz Dedication This work is dedicated to Andrew. This would never have been completed without your love, sense of humor and support. ii Biography Elizabeth Dodge Blue was born in 1975 in Milledgeville, GA to Frederick and Mary Dodge. Years through age 11 were spent in the Baldwin County public schools and trying to do everything her brother Bryan, four years senior, could do including soccer, reading maps, bicycle stunts and climbing fences. In 1987, the Dodge family relocated to Marion, NC, where she completed secondary school at East McDowell Junior High and McDowell High in 1994. She continued her education by pursuing a Chemical Engineering degree at NC State University. At NC State, she enjoyed participating in the NCSU chapter of Habitat for Humanity, as well as cheering on the Wolfpack. She worked for three semesters as a co-op engineer at the National Starch and Chemical pilot plant in Salisbury, NC, and spent one semester taking no technical classes at all in Santander, Spain. One fateful night during exam week sophomore year, she met Andrew Blue, who married her upon her graduation, even though she took some of his pizza. After graduating in Chemical Engineering with a Spanish minor in 1999, Elizabeth went to work as a process engineer for Allied Signal/Honeywell in Moncure, NC. After deciding that teaching was her calling, Elizabeth returned to NC State in 2001 to pursue studies in Chemistry under the direction of Brent Gunnoe. After numerous years pursuing copper amido and nitrene chemistry in the Gunnoe group, she graduated in June 2006. iii Acknowledgements I would like to thank my advisor, Brent Gunnoe, for lots of patience and for being an excellent mentor, and for always keeping me on my toes with his dry wit! I couldn't imagine working under the direction of anyone else. Many, many, innumerable thanks for everything to the entire Gunnoe group, past and present: Dave, Prakash, Ben, Marty, Yuee, Karl, Colleen, John, Laurel, Sam, Nick, Tai and Hong Yan. Y'all are the greatest and I've really enjoyed working with you. Best of luck in all you do in the future – I know you will all be great successes. Thanks especially to Team Copper and the glovebox 3 peeps! Thanks to my committee members: Jim Martin, Dave Shultz, Christian Melander, Mike Whangbo, Paul Maggard, and Fred Lado for your advice and help. Thanks to Paul Boyle for all your assistance in collecting X-ray data and for the help finding, interpreting, and managing structures. Thanks to Dr. Petersen at WVU for solving lots of my crystal structures – even the ones that weren't exactly what we thought they were going to be! Thanks to Brent, Greg Neyhart, and Jim Martin for taking a chance and letting me teach in their courses. And before I get in trouble, I would like to thank my husband, Andrew Blue, and my parents, Fred and Mary Dodge, and for all their love and support. Andrew, I can’t thank you enough for all of your patience and encouragement. You’ve seen me at my worst, and for some reason, stuck around! Mom and Dad, you have taught me so much, above all to try my best and to believe in myself. Many thanks for all that you have taught me and done, and for all the great meals you brought for the freezer. Also, thanks to the rest of my family and to the Blue clan for all their love and support through the years. Last, but not least, thanks to iv the Natureboys for being my main source of entertainment and stress-relief! To Mrs. Harwood for all the funny postcards, and to all my other friends and family members who have encouraged me and made me laugh over the years. v Table of Contents List of Figures ......................................................................................................................... ix List of Tables.........................................................................................................................xiii List of Schemes ..................................................................................................................... xiv List of Symbols and Abbreviations...................................................................................... xvii Chapter 1: Introduction......................................................................................................... 1 1.1 Introduction to Homogeneous Catalysis and Transition-Metal Non-Dative Complexes... 1 1.1.1 Bonding in Late Transition-metal Non-dative Complexes ........................................ 2 1.1.2 Paucity of Monomeric Cu(I) Amido Complexes and Cu(I)OR Complexes.............. 6 1.2 Late Transition-Metal Amido Complexes.......................................................................... 7 1.2.1 Synthesis of Late Transition-metal Amido Complexes ............................................. 7 1.2.2 Reactivity of Relevant Late Transition-metal Amido Complexes............................. 9 1.2.3 Basicity and Nucleophilicity Studies ......................................................................... 9 1.2.4 Stability of Anilido Complexes................................................................................ 17 1.2.5 Amination Catalysis................................................................................................. 19 1.2.6 Aryl Amination ........................................................................................................ 20 1.2.7 Pd Mechanism (Hartwig/Buchwald)........................................................................ 22 1.2.8 Cu Aryl Amination Catalysis................................................................................... 23 1.2.9 Cu Mechanism ......................................................................................................... 25 1.2.10 Hydroamination........................................................................................................... 26 1.3 Late Transition-Metal Nitrene Complexes....................................................................... 29 1.3.1 Synthesis of Late Transition-metal Nitrene Complexes .......................................... 29 1.3.2 Aziridination Catalysis............................................................................................. 30 vi 1.3.3 Mechanistic Studies ................................................................................................. 33 1.4 Summary .........................................................................................................................