Grignard Reactions Involving Halogenated Pyrimidines

Generally, there are two pathways that involve Grignard reagents and halogenated pyrimidines. The more common approach shows cross-coupling reactions that utilize a Grignard reagent, either alkyl or aryl, with a variety of halogenated pyrimidines. Typically, these reactions are catalyzed by Fe, Co, Ni, Pd, Mn, or Zn species. Alternatively, but to a lesser degree, halogenated pyrimidines form pyrimidyl Grignard reagents, which then further react either in a cross-coupling manner or via a standard addition process. Finally, there are a few examples in which Grignard reagents react with pyrimidines via an addition process that does not involve a halogen.