Palladium-catalyzed cross-coupling of benzylzinc reagents with methylthio N-heterocycles: A new coupling reaction with unusual selectivity

Benzylzinc reagents undergo palladium-catalyzed cross-coupling reactions wi th methylthio-substituted N-heterocycles in moderate to good yields. 2-(Met hylthio)pyrimidines are particular ly reactive substrates for this reaction . As a result, the regioselectivity of 2,4-bis(methylthio)pyrimidines is op posite to that of their 2,4-dichloropyrimidine analogues. This unusual cros s-coupling reaction offers new flexibility in the regioselective synthesis of substituted pyrimidines and other heterocycles.