N-Phenyl-1-aza-2-cyano-1, 3-butadienes: An intramolecular hetero Diels-Alder strategy for the construction of 1, 4-benzodiazepines
摘要:
A new approach to the construction of tricyclic 1,4-benzodiazepines has been developed, based upon the intramolecular Diels-Alder (IMDA) reaction of 2-cyano-1-azadienes. This study revealed the difficulties inherent to the direct transformation of imine-amide 2 to azadiene 3, but demonstrated the efficiency of the intramolecular [4 + 2] cycloaddition of azadiene 13 as a means to access benzodiazepines 14a,b (3 : 2 mixture; 74% combined yield). (C) 1998 Elsevier Science Ltd. All rights reserved.
N-Phenyl-1-aza-2-cyano-1, 3-butadienes: An intramolecular hetero Diels-Alder strategy for the construction of 1, 4-benzodiazepines
摘要:
A new approach to the construction of tricyclic 1,4-benzodiazepines has been developed, based upon the intramolecular Diels-Alder (IMDA) reaction of 2-cyano-1-azadienes. This study revealed the difficulties inherent to the direct transformation of imine-amide 2 to azadiene 3, but demonstrated the efficiency of the intramolecular [4 + 2] cycloaddition of azadiene 13 as a means to access benzodiazepines 14a,b (3 : 2 mixture; 74% combined yield). (C) 1998 Elsevier Science Ltd. All rights reserved.