Thiourea–Tertiary Amine Promoted Cascade Catalysis: A Tool for Complexity Generation

Abstract

The bifunctional organocatalyst promoted, relay‐cascade catalysis (use of a single catalyst capable of promoting each catalytic cycle in the designed cascade process) has been the hot area of research in recent times, as it enables the green synthesis of complex molecular architectures in an atom, cost, and step‐economic fashion. In this context we summarized the recent developments in the area of the thiourea–tert‐amine based cascade catalysis in the current review article. The discussion was divided into three subsections. double‐, triple‐, and quadruple cascades depending on the number of individual steps involved in the cascade process. In each type there are various combinations of reactions like Michael addition, aldol reaction, Henry reaction, Knoevenagel reaction, cyclization, trans‐esterifications etc. Divergent polycyclic structural frameworks have been achieved employing this cascade catalytic strategy as evidenced in this review. We assume that the current review article would be a handle for the design and development as well as further growth of this potential greener approach.