Dearomatizing Conversion of Pyrazines to 1,4‐Dihydropyrazine Derivatives via Transition‐Metal‐Free Diboration, Silaboration, and Hydroboration.

The efficient dearomatization of pyrazines (I) to 1,4-dihydropyrazines (III) and (V) and 1,2,3,4-tetrahydropyrazine (VII) via addition of boron reagents (II), (IV), and (VI) having B—B, Si—B, and H—B bonds is reported.