Tandem reactions, cascade sequences, and biomimetic strategies in total synthesis.

Cascade reactions and biomimetic strategies are being increasingly applied to the construction of natural and designed molecules. Such processes, in which ideally a single event triggers the conversion of a starting material to a product which then becomes a substrate for the next reaction until termination leads to a stable final product, are highly desirable not only due to their elegance, but also because of their efficiency and economy in terms of reagent consumption and purification. Often, these multistep, one-pot procedures are accompanied by dramatic increases in molecular complexity and impressive selectivity. The discovery of new molecular diversity from Nature and the demand for more efficient and environmentally benign chemical processes dictates and invites the further development of such synthetic strategies and tactics as we move into a new age of chemical synthesis. Within this article, a number of instructive examples of such synthetic strategies from the principal author's laboratories are discussed.