Stille coupling organostannane activation

Cross-couplings. The Stille coupling of organostannanes with hypervalent iodine compounds has a broad scope. Diaryl and dialkenyl tellurides are also active toward alkenes if the catalytic system contains AgOAc. ... 

Following on this discovery, in 1996 Liebeskind reported that copper(I) thiophene-2-carboxylate (CuTC) was able to promote the Stille coupling between organic iodides (mainly vinyl and activated aryl) and organostannanes in the absence of palladium, at or below room temperature in NMP as solvent. " ... 

As seen with the previous example, activation of the organostannane to promote the transmetalation step has a dramatic and positive influence on the outcome of the reaction. In 1992, Vedejs et al. showed that intramolecular coordination of tin by a nucleophilic center like a nitrogen can considerably increase the rate of the transmetalation step in the Stille coupling . Derivatives like 22 proved to be more reactive than their analogue trialkyl tin... 

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