New Synthetic Routes to Strained Cumulenes and Reactive Carbenes
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University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Spring 1998 New synthetic routes to strained cumulenes and reactive carbenes Susana Hernandez University of New Hampshire, Durham Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation Hernandez, Susana, "New synthetic routes to strained cumulenes and reactive carbenes" (1998). Doctoral Dissertations. 2011. https://scholars.unh.edu/dissertation/2011 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. 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Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. UMI A Bell & Howell Information Company 300 North Zed) Road, Ann Arbor MI 48106-1346 USA 313/761-4700 800/521-0600 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. NEW SYNTHETIC ROUTES TO STRAINED CUMULENES AND REACTIVE CARBENES BY SUSANA HERNANDEZ B. A. PEDAGOGIC AND TECHNOLOGICAL UNIVERSITY OF COLOMBIA, 1984 DISSERTATION Submitted to the University of New Hampshire in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in C hem istry May, 1998 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 9831943 UMI Microform 9831943 Copyright 1998, by UMI Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. This dissertation has been examined and approved. sertation Director, Ricbfard P. JohnsonDissertation Professor of Chemistry lorrison, Professor of Chemistry Paul OssemjTuggen, Professor o^zivil Engineering /j-Uui James H. Weber, Professor of Chemistry C l • Q >L_,____ Charles K. Zercher, Associate Professor of Chemistry Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. DEDICATION To my parents, Carlos J. and Maria A., and my brothers and sisters for their love and support. iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGMENTS It is my pleasure to thank Dr. Richard Johnson for his ideas, guidance and support throughout the years. His great efforts as a teacher and research advisor have contributed to make me a better scientist. In addition, I would like to thank him for correcting this dissertation -a text full with commas. Thanks to the other members of my committee, Dr. Charles Zercher, Dr. James Morrison, Dr. Paul Ossenbruggen and Dr. James Weber for their comments and suggestions. Thanks to my professors at the University of New Hampshire from whom I have received much needed help many times. I am greatly indebted to Dr. Edward Wong, Dr. Gary Weisman, Dr. Dennis Chasteen and Dr. Sterling Tomellini. I must thank Kathy Gallagher for her help with the Bruker and for her friendship. The people I have met these past years at UNH have made my stay enjoyable. M any thanks to all! iv Reproduced with permission of the copyright owner. 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TABLE OF CONTENTS DEDICATION......................................................................................................................iii ACKNOWLEDGEMENTS................................................................................................iv TABLE OF CONTENTS..................................................................................................... v LIST OF SCHEMES.............................................................................................................ix LIST OF FIGURES.............................................................................................................xvi LIST OF TABLES............................................................................................................xviii ABSTRACT......................................................................................................................... xix CHAPTER PAGE GENERAL INTRODUCTION...........................................................................................1 I. DEVELOPMENTS IN THE SYNTHESIS OF STRAINED CYCLIC BUTATRIENES.........................................................................................................2 Introduction to Strained Molecules ........................................................2 Strained Cyclic Butatrienes .........................................................14 Statement of the Goals ................................................................. 22 Results and Discussion ............................................................................ 22 Redefining The Isolability Limit for Cyclic Butatrienes ..........................................................................22 Synthesis of 1,2,3-Cyclooctatriene ................................22 v Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. I. DEVELOPMENTS IN THE SYNTHESIS OF STRAINED CYCLIC BUTATRIENES (cont.) New Route to 1,2,3-Cycloheptatriene .........................30 Strain Estimates in Cyclic Butatrienes ; ................. 34 Introduction ....................................................................... 34 Homodesmic and Isodesmic Reactions .....................35 Strain Estimates in 1,2,3-Cyclooctatriene .................. 39 Strain Estimates in 1,2,3-Cycloheptatriene ............... 42 New Route to Cydohepten-3-yne ............................... 46 Strain Estimates in Cyclohepten-3-yne ......................49 Redefining Structural Limitations for Cyclic Butatrienes .......................................................................... 53 1,2,3-Cyclopentatriene 53 Synthesis of Potential Precursors for 5,5-DimethyI-l/2/3-pentatriene and their Exploratory Reactions ..................................................... 55 Conclusion and Future Work ....................................... 81 Attempted Synthesis of Cyclic Butatrienes by Intramolecular Vinylidene Coupling ..................................... 83 Synthesis of Tetrabromo-olefins and their Reaction with Cu(I).............................................. 84 Conclusion ........................................................................ 91 v i Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. E. PHOTOGENERATION OF REACTIVE CARBENES BY FRAGMENTATION OF CYCLOPROPANATED PHENANTHRENES......................................................................................93 Introduction ................................................................................................93 Definitions and Nomenclature .................................................93 Structure and Reactivity of Carbenes ......................................95 Generation and Reactions of Carbenes ...................................97 Results and Discussion .......................................................................... 104 Research Goals.............................................................................104 Photochemical Generation of Vinylcarbene and Trapping of Cyclopropene ................................................106 Synthesis of Precursors to Simple Vinylidenes and Photogeneration of 1-Nonyne .................................................112 Cyclic Vinylidenes ......................................................................117 Synthesis of a Cyclobutylidenecarbene Precursor and Photogeneration of Cydopentyne ..................................118 Synthesis of a Cyclopentylidenecarbene Precursor and Photogeneration of a C6 Vinylidene ...................................... 126 Synthesis of a Cyclohexylidenecarbene Precursor