Preparation and electrophilic cyclization of multisubstituted dienamides leading to cyclic iminoethers.
Stereodefined multisubstituted dienamides could be concisely prepared in high yields by direct addition of 1-lithiobutadiene derivatives to both N-aryl and N-alkyl isocyanates. Electrophilic cyclization of these dienamides was achieved to generate substituted cyclic iminoethers in excellent yields with perfect selectivity. When treated with 12 N aqueous HCl, dienamides underwent efficient and selective electrophilic cyclization to afford cyclic imidate derivatives. When treated with NBS, monobrominated or double-brominated cyclic iminoethers were formed.
Wang
Congyang
C
Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China.
Lu
Jiang
J
Mao
Guoliang
G
Xi
Zhenfeng
Z