Domino Reactions in the Build-Couple-Pair Approach for Library Synthesis

Domino Reactions in the Build-Couple-Pair Approach for Library Synthesis 

In the build-couple-pair approach to library synthesis, the building blocks are first synthesized from commercial material (build phase), which are then coupled to form a substrate (couple phase) that can further react under certain conditions and pair itself intramolecularly to form the cyclic products depicting the scaffold framework [24]. It is in the last two steps that the domino reaction can intervene to yield a more complex scaffold and with higher ring diversity. 

Schreiber and Luo exploited domino sequences in both the coupling and pairing phases [25]. A gold-catalyzed cyclization of alkyne 157 was employed to obtain molecules that could subsequently be used in the pairing reaction. Activation of the alkyne by a gold(I) complex yielded the cydized cationic species 160, 

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