ABSTRACT
While enantioselective reactions can, in the broadest sense, be understood as reactions in which enantiomerically pure compounds are produced, this section will be mostly concerned with reactions in which a new element of chirality is created from achiral starting materials. Auxiliary-induced diastereoselective reactions are therefore not covered by this review. Due to the increasing importance of helically and axially chiral compounds, we have, however, added a section on chirality transfer and chiral memory phenomena. In general, emphasis was put on recently reported work ideally with a synthetic relevance. Previous reviews on the topic have appeared in journals1 and in books, for example, in Volume 11 of the Molecular and Supramolecular Photochemistry series,2 and the reader is referred to Chapter 61 in the second edition of this handbook3 as a guideline to older reviews about stereoselective photocycloaddition reactions. Recent reviews on photochemical reactions in total synthesis4,5 might be useful for those interested in the preparative aspects of photochemistry. In addition, two chapters in this handbook, on photochemistry in con„ned media (Chapter 11) and on photochirogenesis (Chapter 6), deal with closely related topics. Finally, it should be mentioned that this account deals exclusively with solution-phase photochemistry.
