Macrocycles multicomponent synthesis using

Abstract How to access efficiently the macrocyclic structure remained to be a challenging synthetic topic. Although many elegant approaches/reactions have been developed, construction of diverse collection of macrocycles is stiU elusive. This chapter summarized the recently emerged research area dealing with multi-component synthesis of macrocycles, with particular emphasis on the approach named multiple multicomponent reaction using two bifunctional building blocks . 

The development of multicomponent synthesis of macrocycles is highly challenging. To facilitate the discussion, we use the transformation shown in (1) of Scheme 3 to illustrate the inherent difficulties associated with this approach. To make this approach successful, the fate of intermediate 9 ((1), Scheme 3) is a... 

The synthesis of a small library of very large (up to 60-membered) steroid/ peptide hybrid macrocycles has been achieved using double and fourfold Ugi reactions. This type of compound has not previously been described in literature. Neither have multicomponent reactions been used so far to form directly macrocycles of this size. In fact, synthetic macrocycles of this size with this structural complexity are very rare. 

Much attention is currently devoted to the synthesis and properties of shape-persistent macrocycles[l]. Such compounds are interesting for a variety of reasons including formation of columnar stacks potentially capable of performing as nanopores for incorporation into membranes or for the generation of nanowires[2]. Furthermore, in shape-persistent macrocycles incorporating coordination units, enc/o-cyclic metal-ion coordination may be exploited to generate nanowires[3], whereas e.ro-cyclic coordination can be used to construct large arrays of polynuclear metal complexes[4]. Shape-persistent macrocycles with reactive substituents may also be linked to other units to yield multicomponent, hierarchical structures. 

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