Preface
Organolithiums are versatile, widely used reagents and intermediates in organic synthesis. As part of the accelerating interest in developing methods for asymmetric synthesis, the use of organolithiums in enantioselective synthesis has witnessed spectacular advances in the last dozen years. This volume constitutes the first comprehensive treatise of this exciting area. Carving up the field of enantioselective organolithium chemistry into discrete chapters based on the type of process involved is of course to some extent an artificial process and could, no doubt, have been carried out in other ways. Nevertheless, it is believed that the eight main chapters of this volume constitute a reasonable division into the major areas where significant progress has been made. Also, in a multi-author volume of this nature, it is inevitable, and at times desirable (for the completeness of an individual chapter) that there is the occasional slight overlap of content between chapters. It must also be accepted that the level of detail and style of chapters will differ, as each contribution brings a flavour of the author's own knowledgeable views to the precise area under discussion. For example, several chapters include appropriate background on diastereoselective (especially chiral auxiliary) based approaches to the use of organolithiums in synthesis; this material serves to put the enantioselective (ligandassisted) contributions into proper perspective. I am very grateful to my fellow chemists who generously put their expertise into this project: P. Beak, M. Brüggemann, J. Clayden, B. Goldfuss, E. Gras, D. Hoppe, M. Iguchi, T. A. Johnson, D. D. Kim, S. H. Lim, F. Marr, S. Nakamura, J. F. Normant, M. A. H. Stent, K. Tomioka, K. Tomooka, T. Toru, and K. Yamada. I am also grateful to J. Brown (Oxford) for encouragement and C. Moisa (Springer) for help with the preparation of this volume. Oxford, January 2003
David Hodgson
Topics Organomet Chem (2003) 5: 1–20 DOI 10.1007/b10341
Overview of Organolithium-Ligand Combinations and Lithium Amides for Enantioselective Processes David M. Hodgson, Matthew A. H. Stent Dyson Perrins Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QY, U.K. E-mail:
[email protected]
The first reports of the use of additives to induce enantioselectivity in reactions of organolithiums appeared in the late 1960s, with widespread interest developing from the late 1980s onwards mirroring the heightened interest in asymmetric synthesis. This chapter provides an overview of the use of external chiral ligands as the source of enantioinduction in organolithium processes, mainly in the areas of asymmetric additions and enant