Introduction

Catalysis is associated with chemical and biological sciences as an underlying factor to ease the formation of products for specific purposes. Supramolecular aspects introduced into the topics of catalysis and their molecular understanding enable one to execute many difficult tasks, such as using synthetic molecules to mimic natural processes. The ease of performing a reaction by constructing one's own reaction vessel and using one's own transport system to mix components in natural catalytic reactions has generated curiosity and the inspiration to mimic natural catalytic processes and apply them in the realm of the synthetic world. The motivation to improvise such methodologies in the fields of fuel, medicine and environment has led to the development of catalysts with new features. The implications of the lock-and-key mechanism of enzymes have been brought to complementary weak interactions and molecular recognitions in host–guest systems. This chapter introduces the fundamentals of those aspects of supramolecular chemistry by introducing energetics and the role of weak interactions. Self-assembly's help in electron transfer and the crown effect influencing catalytic activities are dealt with. Inclusion, recognition and complementary interactions to bring together reactants and delineate chemical aspects to suggest their roles in catalytic reactions are addressed. Conformation-guided catalytic processes, bifunctional catalysts, intermediates for chiral induction, contact catalysts and surface modifications are discussed to provide the fundamental basis of supramolecular catalysis. Two component catalysts, one component activating the reagent and the other activating the intermediate assisted by hydrogen-bonded assembly, are presented. Structural modifications to cause coordination unsaturation through supramolecular features for catalytic reactions are shown.