Novel and green protocol for the synthesis of 2-iminohydantoins
摘要:
A novel and green protocol for the synthesis of N-1 and C-5 substituted 2-iminohydantoins has been developed. Methyl N-cyano-N-alkyl/aryl-aminoacetate reacts with aqueous ammonia at room temperature in 10-30 min. The developed protocol does not require any work-up for the isolation or purification of the products; simple filtration can lead to the pure products in good to excellent yields. (C) 2012 Elsevier Ltd. All rights reserved.
An unprecedented copper and in situ-generated triflic acid relay-promoted four-component cascade reaction of cyanamides, diaryliodonium triflates, propargylic amines, and H2O was established for rapid and concise construction of diverse five-membered cycloguanidines. Copper-catalyzed guanidination/intramolecular hydroamination and in situ-generated HOTf-accelerated hydration proceeded sequentially