New trends in dimetallic synthons
Abstra In principle. organic molecules bearing two reactive organometallic functionalities are valuable synthons for the introduction of the organic moiety as a bifunctional nucleophilic reagent; in this regard, they supplement the better known and more widely applied organic dihalides (or their equivalents). which find use as bifunctional electrophilic reagents. While a number of simple larger dimetallic species have been known and applied for a long time, much less was known until recently on small dimetallic species in which the organometallic functions are separated by one, two, or three carbon atoms only. We have been engaged in a programme to make such small dimetallic species available, in particular in the field of 1 ,l-, 1,2and 1,3-diGrignard reagents and, to a lesser extent, their dilithio analogues. Up till now, a large part of our effort has been devoted to the development of these reagents, either by improving known syntheses or, in many cases, by making the reagents accessible for the first time. The synthetic utility of these reagents has been demonstrated by a broad range of novel organometallic compounds; the exploration of purely organic applications has also been initiated.