Fundamental mechanistic characteristics and synthetic applications of allylations promoted by indium metal in aqueous media

An overview is provided of the utilitarian role that allylindation under aqueous conditions can play in a variety of synthetic contexts. These include the diastereoselective allylation of chiral aldehydes, the consequences of coupling geometrically biased allylic bromides, the realization of 1,4-asymmetric induction, and an analysis of competitive intramolecular/intermolecular chelation options. Also presented are the results of diastereoselective additions to alpha-oxygenated ketones and to 2,3-azetidinediones. Synthetic applications include a practical alternative to the Knoevenagel reaction of aliphatic aldehydes, the formation of alpha-methylene-gamma-lactones fused to medium and large rings, and the intercalation of multiple carbon atoms between the carbonyls of alpha-diketones.