Metal catalyzed allylic alkylation: its development in the Trost laboratories

Abstract

I am highly honored to be the co-recipient of the Tetrahedron Prize for 2014 with Professor Jiro Tsuji for our work on metal catalyzed allylic alkylation, notably that using palladium. In the context of this award, this report deals only with the evolution of our work. Nevertheless, it is important to note that innumerable groups around the world have and are playing essential roles metal catalyzed allylic alkylations. The reader can find citations to such work in the references to our work that appears in this report. My involvement with this field derived from work in my laboratory dealing with the structure determination and synthesis of the insect juvenile hormone.1 The juvenile hormone is one of three hormones that control the stages of insect development from the pupae to the larvae and finally to the adult. Thus, these hormones, most notably the juvenile hormone that prevented molting was targeted as a potentially more environmentally benign insecticide. The structural relationship of the insect juvenile hormone and methyl farnesoate suggests a possible biosynthetic pathway may be involving the homologation of two of the olefinic methyl groups to ethyl groups. Such an approach, if feasible, would be very attractive, short, and potentially very practical. Unfortunately, such a synthetic protocol did not exist – a fact that intrigued me. While the reactions of the oxygen analog wherein alkylation at the carbon adjacent to the π-unsaturated carbonyl group is one of the most important synthetic reactions, the inability of the all carbon analog to undergo a similar transformation was very attractive.