Stereoselective Capture of N‑Acyliminium Ions Generated from α‑Hydroxy‑N‑acylcarbamides: Direct Synthesis of Uracils from Barbituric Acids Enabled by SmI2 Reduction
2015-12-17T00:17:38Z (GMT) by
Lewis acid promoted cleavage of α-amino alcohols derived from barbituric acids via chemoselective Sm(II)-mediated electron transfer affords a wide range of C6-substituted 5,6-dihydrouracils. The reaction involves the first generation of N-acyliminium ions directly from the versatile barbituric acids and proceeds with excellent stereoselectivity. The products are shown to be active in generic transition metal catalyzed reactions, thus providing a modular and highly practical sequence to the biologically significant uracil derivatives.
CC BY-NC 4.0