Bismuth Linker Units

The use of triarylbismuth(III) species, particularly in arylation reactions, is a growing area of research in organic synthesis that has been recently reviewed. Unlike the related palladium-catalyzed cross-coupling reactions, which often require development of substrate-specific reaction conditions, the organobismuth reactions appear more versatile. This simple chemistry, in addition to the broad range of applications, makes 

LINKER STRATEGIES IN MODERN SOLID-PHASE ORGANIC SYNTHESIS 

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Beyond RCM and CM strategies, Craig has reported cleavage using Diels-Alder reactions (Scheme 1.16). ° [4 + 2] Cycloaddition (with concomitant aromatization) of the o-quinodimethane precursor (52) with dimethylacetylene dicarboxylate (DMAD), trichlor-oacetonitrile, and benzoquinone provided dimethyl naphthalene-2,3-dicarboxylate (53), 3-(trichloromethyl)isoquinoline (54), and 2,3-naphthoquinone (55), respectively. The diverse products from a single polymer-supported intermediate, such as the bismuth linkers discussed previously, make Craig s multifunctional linker unit attractive for approaches toward diversity-oriented synthesis. 

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