Overcoming Reactive-Pair Mismatch to Access Functionalized Pyrimidines from Readily Accessible Pyrroles.

A heterocycle remodeling protocol for transforming readily accessible C2/C5-functionalized pyrroles into substituted pyrimidines via nitrogen atom insertion has been developed, using sulfenylnitrene as the nitrogen source. This method enables direct access to functionalized pyrimidines under mild conditions, without relying on metals or the selective incorporation of halogens into pyrimidines, and is applicable to the synthesis of sterically hindered pyrimidines, such as 2,4-ditritylpyrimidine, which were previously inaccessible.