Synthesis of novel synthetic intermediates from the reaction of benzimidazole and triazole carbenes with ketenimines and their application in the construction of spiro-pyrroles.
2-(2-Alkoxycarbonyl-1-arylamino-1-propenyl)benzimidazolium and 5-(2-alkoxycarbonyl-1-arylamino-1-propenyl)triazolium salts were synthesized in good yields from the reaction of benzimidazole and triazole carbenes with ketenimines. Upon treatment with a base, both salts were converted into novel 1,3-dipoles which underwent [3+2] cycloaddition reactions with electron-deficient alkynes and allenes to produce benzimidazole-spiro-pyrroles or triazole-spiro-pyrroles. This work provides novel synthons for the construction of multifunctional spiro-pyrrole derivatives that are not easy accessible by other synthetic methods and are potentially amenable to further transformations.
Mo
Jun-Ming
JM
College of Chemistry, Beijing Normal University, Beijing 100875, China.
Ma
Yang-Guang
YG
Cheng
Ying
Y
D001562:Benzimidazoles / Q000737:chemistry*; D003500:Cyclization; D007097:Imines / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D014230:Triazoles / Q000737:chemistry*
D001562:Benzimidazoles; D007097:Imines; D011758:Pyrroles; D013141:Spiro Compounds; D014230:Triazoles; C030011:carbene; C031000:benzimidazole; D008697:Methane