Synthesis, Polymerization and Reactions of Enantiomerically Pure Phosphaalkenes by Spencer Christopher Serin B.Sc. (Hons.) The University of Western Ontario, 2010 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Chemistry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2016 © Spencer Christopher Serin, 2016 Abstract This thesis outlines the polymerization and novel reactivity of enantiomerically pure compounds featuring the relatively uncommon phosphaalkene moiety. Chapter 1 introduces the chemistry of the phosphaalkene (Ar-P=CR2) structural fragment. This motif is compared and contrasted to the established chemistry of C=N and C=C groups. Similarities and differences are highlighted by an examination of: (a) phosphaalkene synthesis, (b) phosphaalkene polymerization and (c) phosphaalkene-metal coordination. Chapter 2 details the addition reactions of MeM (M = MgBr, Li) nucleophiles to enantiomerically pure phosphaalkene-oxazoline 1.10a [PhAk-Ox, MesP=CPh(CMe2Ox)]. Of note, the reaction of MeMgBr and PhAk-Ox is highly diastereoselective and affords a new P-chiral phosphine oxazoline ligand. Chapters 3 and 4 report the free radical initiated homo- and co-polymerizations (with styrene) of enantiomerically pure phosphaalkene-oxazolines 1.10a (Chapter 3) and 4.1a [MesP=CPh(3-C6H4Ox), Chapter 4]. The coordination of rhodium(I) to copolymers of 1.10a and styrene permits the isolation of novel macromolecular complexes. Additionally, polymers of 4.1a display unique spectroscopic signatures that permit the direct assignment of styrene- phosphaalkene linkages in the polymer backbone. Chapters 5 and 6 highlight the coordination chemistry of phosphaalkenes. Chapter 5 discusses the syntheses of κ3(PNN)-copper(I) complexes featuring enantiomerically pure pyridine- bridged phosphaalkene-oxazoline 5.1a [ArP=CPh(2-C5H3N-6-Ox)]. Chapter 6 explores the insertion of the P=C functional group into Pd–R bonds, permitting the synthesis of novel ii phosphapalladacyclopropanes (6.1a-b) and palladium(II) complexes featuring 1,2- dihydropyridinato donors (6.3 and 6.4). Chapter 7 provides perspective for the work contained within this thesis. iii Preface Sections of this work have previously been published. Sections of the introductory Chapter 1 have been published in Chemical Society Reviews, for a review on main group containing polymers which was written in equal collaboration with Andrew M. Priegert and Benjamin W. Rawe along with our supervisor Prof. Derek P. Gates. Andrew M. Priegert, Benjamin W. Rawe, Spencer C. Serin and Derek P. Gates. Polymers and the p-block elements. Chem. Soc. Rev. 2016, 45, 922-953. The information presented in Chapter 2 has been published in Organometallics, for which I performed all the synthetic work and wrote the manuscript in collaboration with both my supervisors Prof. Gregory R. Dake and Prof. Derek P. Gates. The X-ray data was collected, integrated, refined, and solved by myself, however one structure was refined and solved by Dr. Brian O. Patrick. Spencer C. Serin, Brian O. Patrick, Gregory R. Dake and Derek P. Gates. Reaction of an Enantiomerically Pure Phosphaalkene-Oxazoline with MeM (M = Li and MgBr): Stereoselectivity and Noninnocence of the P-Mesityl Substituent. Organometallics 2014, 33, 7215-7222. The information in Chapter 3 has been published in two separate journal articles. The first report of a copolymer obtained from an enantiomerically pure phosphaalkene-oxazoline was published in Chemistry – A European Journal¸ for which I performed all the synthetic work, wrote the experimental, and prepared the figures pertaining to the copolymer. This work also detailed the synthesis of a number of phosphaalkene-oxazolines for which the synthetic work was performed and written by the other authors. Julien Dugal-Tessier, Spencer C. Serin, Emmanuel B. Castillo-Contreras, Eamonn D. Conrad, Gregory R. Dake and Derek P. Gates. Enantiomerically Pure Phosphaalkene-Oxazolines (PhAk-Ox): Synthesis, Scope and Copolymerization with iv Styrene. Chem. Eur. J. 2012, 18, 6349-6359. Additional copolymers, microstructure analysis and rhodium(I) coordination to these copolymers was published in Dalton Transactions, for which I performed all the synthetic work, X-ray analysis, and wrote the manuscript in collaboration with my supervisors Prof. Gregory R. Dake and Prof. Derek P. Gates. Spencer C. Serin, Gregory R. Dake and Derek P. Gates. Phosphaalkene-oxazoline Copolymers with Styrene as Chiral Ligands for Rhodium(I). Dalton Trans. 2016, 45, 5659-5666. The work in Chapter 4 has been published in Macromolecules, for which I performed all the synthetic work, X-ray analysis, and wrote the manuscript in collaboration with my supervisors Prof. Gregory R. Dake and Prof. Derek P. Gates. Spencer C. Serin, Gregory R. Dake and Derek P. Gates. Addition-Isomerization Polymerization of Chiral Phosphaalkenes: Observations of Styrene-Phosphaalkene Linkages in a Random Copolymer. Macromolecules 2016, 49(11), 4067- 4075. The work in Chapter 5 has been published in Inorganic Chemistry, for which I performed all the synthetic work, X-ray analysis and wrote the manuscript in collaboration with my supervisors Prof. Gregory R. Dake and Prof. Derek P. Gates. Computational data was obtained by Fraser S. Pick. Spencer C. Serin, Fraser S. Pick, Gregory R. Dake and Derek P. Gates. Copper(I) Complexes of Pyridine-Bridged Phosphaalkene-Oxazoline Pincer Ligands. Inorg. Chem. 2016, 55(13), 6670-6678. The work in Chapter 6 will be submitted shortly for publication and I performed all the synthetic work and X-ray analysis. Spencer C. Serin, Gregory R. Dake, Derek P. Gates, to be submitted v Table of Contents Abstract .......................................................................................................................................... ii Preface ........................................................................................................................................... iv Table of Contents ......................................................................................................................... vi List of Tables ............................................................................................................................... xii List of Figures ............................................................................................................................. xiii List of Schemes ........................................................................................................................... xvi List of Abbreviations and Symbols .......................................................................................... xix Acknowledgements ....................................................................................................................xxv Dedication ................................................................................................................................. xxvi Foreword .................................................................................................................................. xxvii Chapter 1: Introduction: Phosphaalkenes as Monomers and Ligands ....................................1 1.1 Introduction ..................................................................................................................... 1 1.1.1 Low-Coordinate Phosphorus ...................................................................................... 2 1.1.2 Synthetic Approaches to Phosphaalkenes ................................................................... 4 1.1.2.1 Synthesis of Achiral Phosphaalkenes ................................................................. 5 1.1.2.2 Synthesis of Enantiomerically Pure Phosphaalkenes ......................................... 6 1.2 Phosphaalkenes as Monomers ........................................................................................ 9 1.3 Phosphaalkenes as Ligands ........................................................................................... 14 1.3.1 Coordination Properties of Phosphaalkenes ............................................................. 14 1.3.2 Selected Complexes that Feature Phosphaalkenes ................................................... 16 1.3.3 Phosphaalkenes as Ligands for Catalysis ................................................................. 17 vi 1.4 Goal of the Project ........................................................................................................ 21 1.5 Outline of Thesis ........................................................................................................... 21 Chapter 2: Reaction of an Enantiomerically Pure Phosphaalkene-Oxazoline with MeM Nucleophiles (M = Li and MgBr) ................................................................................................23 2.1 Introduction ................................................................................................................... 23 2.2 Results and Discussion ................................................................................................. 24 2.2.1 General Synthetic Strategy ....................................................................................... 24 2.2.2 Analysis of MeMgBr Addition to Phosphaalkene 1.10a .......................................... 26 2.2.2.1 Synthesis of Chiral Phosphine-Oxazoline 2.1a,a ............................................... 26 2.2.2.2 Postulated Mechanism