A one-pot multicomponent coupling/cyclization for natural product herbicide (±)-thaxtomin A

Herbicide (±)-thaxtomin A has been synthesized in a one-pot process with a 32% isolated yield. A multicomponent coupling reaction was utilized to prepare in situ a dipeptide precursor which then sequentially underwent an alkaline mediated keto-amide cyclization to provide the target molecule. Adjustment of diastereoselectivity was achieved using microwave-induced irradiation. The approach incorporates atom economy and reaction efficiency and allows for facile library development.