Abstract:
A natural driving force is always working behind the synthetic organic chemists towards the development of
‘green’ synthetic methodologies for the synthesis of useful classes of organic molecules having potential applications. The
majority of the essential classes of organic transformations, including C-C and C-X (X = heteroatom) bond-forming crosscoupling
reactions, cross dehydrogenative-coupling (CDC) mostly rely on the requirement of transition-metal catalysts and
hazardous organic solvents. Hence, the scope in developing green synthetic strategies by avoiding the use of transitionmetal
catalysts and hazardous organic solvents for those important and useful classes of organic transformations is very
high. Hence, several attempts are made so far. Water being the most abundant, cheap, and green solvent in the world;
numerous synthetic methods have been developed in an aqueous medium. In this review, the development of transitionmetal-
free green synthetic strategies for various important classes of organic transformations such as C-C and C-X bondforming
cross-coupling, cross dehydrogenative-coupling, and oxidative-coupling in an aqueous media is discussed.
Copper(ii)-catalyzed synthesis of multisubstituted indoles through sequential Chan–Lam and cross-dehydrogenative coupling reactions