Frustrated Lewis Pairs Based on Transition Metals

The concept of frustration and its application to bond activation and catalysis over the last decade has paved the way to a new era in the field of main group chemistry. In terms of catalysis, the introduction of transition metals as integrating components of frustrated designs has emerged as a promising approach to overcome the main limitations of main group FLP systems. Herein we have tried to summarize the most relevant results in this flourishing field, particularly those described over the last five years (187 references are included). It is our aim to provide a Chapter that will serve as an illustrative outline to those already working in the area of frustrated Lewis pairs and also as an inspiring guide to newcomers. After a general introduction covering the main goals associated to the idea of designing metallic FLPs, a subsequent section deals with transition metal frustrated Lewis pairs that incorporate a single transition metal center. A wide variety of recent examples based on early, mid- and late transition metals, as well as rare-earth elements is presented. The next topic involves the rather limited and exotic examples in which the two components of the FLP are based on transition metals. The connection of these systems to polarized heterobimetallic species is examined in detail. Bond activation processes and catalytic applications are discussed along the text, with particular emphasis on mechanistic aspects.