A general and stereoselective approach to 14-membered cyclic bis-semicarbazones involving BF3-catalyzed amidoalkylation of 2-(trimethylsilyloxy)propene.
Org Biomol Chem
; 20(22): 4569-4588, 2022 06 08.
Article
em En
| MEDLINE
| ID: mdl-35593300
ABSTRACT
A general and stereoselective five-step approach to 14-membered cyclic bis-semicarbazones, 5,12-diaryl-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-diones, starting from aldehyde semicarbazones has been developed. The key intermediates, 4-(3-oxobut-1-yl)semicarbazones, were prepared by BF3-catalyzed amidoalkylation of 2-(trimethylsilyloxy)propene with 4-[(aryl)(methoxy)methyl]- or 4-[(aryl)(tosyl)methyl]semicarbazones. Treatment of these intermediates with excess of hydrazine gave hydrazones of 4-(3-oxobut-1-yl)semicarbazones or 4-(3-oxobut-1-yl)semicarbazides, which in the presence of TsOH were converted into the target macrocycles. All steps of this approach could be scaled up easily to the multi-gram level.
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1
Base de dados:
MEDLINE
Assunto principal:
Semicarbazonas
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article