Stereoselective oxa-Michael addition of tyrosine to propargyl aldehyde/esters: formation of benzofurans and flavones
Adv Synth Catal, v. 361, p. 4243-4254
Article
em En
| SES-SP, SESSP-IBPROD, SES-SP
| ID: bud-3028
Biblioteca responsável:
BR78.1
ABSTRACT
The steroselective oxa-Michael addition of the phenol moiety present in tyrosine and 3-iodotyrosine to different propargyl aldehydes delivered products with predominantly Z stereochemistry, as evidenced by X-ray crystallography analysis. When ethyl ropiolate was used as the propargyl ester source, the products were achieved with exclusively E stereochemistry with yields ranging from 17% to 91%. The oxa-Michael addition compounds served as substrates in the synthesis of 5- and 6-membered heterocyclic compounds. The atmosphere applied to the reaction medium directly influenced the formation of the products. When an inert atmosphere of nitrogen was applied, a 2-aryl-3-formyl-5-alanylbenzofuran core was selectively obtained via a Heck intramolecular reaction, while the reactions carried out under a carbon monoxide atmosphere led exclusively to 6-alanyl-2-arylflavone derivatives via reductive intramolecular acylation.
Texto completo:
1
Coleções:
06-national
/
BR
Base de dados:
SES-SP
/
SESSP-IBPROD
Idioma:
En
Revista:
Adv Synth Catal
Ano de publicação:
2019
Tipo de documento:
Article