Non-Isocyanide-Based Three-Component Reactions: From Strecker to Nowadays

Almost two centuries have passed since Strecker synthesized for the first time the alpha-aminoacid DLalanine via a sequential combination of acetaldehyde with aqueous ammonia and hydrogen cyanide, coupled to a further hydrolysis of the resulting alpha-aminonitrile using an acid aqueous solution. Since then, a broad variety of high valued products in various fields of science and technology have been synthesized via three-component reactions (3CRs) or via one-pot methodologies involving 3CRs coupled smartly to further processes like functionalizations, condensations, cross couplings, cyclizations, ring openings, and so on. In the same way, very interesting and useful computational calculations behind understanding reaction mechanisms related to 3CRs, conformational analyses, and energy profiles have been performed. All these topics are on the scope of the present review, which covers selected and elegant based 3CRs (except for the Ugi-3CR or its variants), and other unclassified 3CR-based works from 2010 to nowadays.