Annulation of Thiolmidates and Vinyl Carbodiimides to Prepare 2-Aminopyrimidines, Competent Nucleophiles for Intramolecular Alkyne Hydroamination. Synthesis of (-)-Crambidine

A convergent synthesis of(-)-crambidine is reported. The sequence Capitalizes on two novel key transformations, including.(I) a [4+2] annulation of thioimidates with vinyl carbodiimides and an alkyne hydroamination employing 2-aminopyrimidine nucleophiles.