Efficient Synthesis of 1,3,5-Trisubstituted (Pyrrol-2-yl)acetic Acid Esters via Dual Nucleophilic Reactions of Sulfonamides or Carbamate with 4-Trimethyl-siloxy-(5<i>E</i>)-hexen-2-ynoates: Lewis Acid Catalyzed S<sub>N</sub>1 and Intramolecular Michael Addition
作者:Teruhiko Ishikawa、Toshiaki Aikawa、Shinichiro Watanabe、Seiki Saito
DOI:10.1021/ol0616485
日期:2006.8.1
Carbamates or sulfonamides have proven to regioselectively attack 2-propynyl-allyl hybrid cations, generated by the action of TMSOTf on 4-(trimethylsioxy)hex-5-en-2-ynoates, to afford conjugated 6-aminohex-4-en-2-ynoates in which an intramolecular amino-Michael reaction took place, leading to pyrrole frameworks. In particular, the sulfonamides gave 1-sulfonylpyrroles in one pot.