Regiocontrolled and Stereoselective Syntheses of Tetrahydrophthalazine Derivatives using Radical Cyclizations.
Chemistry
; 25(4): 976-980, 2019 Jan 18.
Article
em En
| MEDLINE
| ID: mdl-30350381
ABSTRACT
Tetrahydrophthalazine derivatives have found important applications in pharmaceutical research, but existing synthetic methods are unable to access them regio- and stereoselectively. Here, a new approach is presented that addresses these challenges by utilizing a 6-endo-trig radical cyclization in the key step. The desired tetrahydrophthalazines can be accessed in high yields (55-98 %) and high diastereoselectivities for the trans-product (>955) starting either from readily accessible hydrazones, or from the corresponding aldehydes and substituted Boc-hydrazides in a one-pot process. The synthetic versatility of the tetrahydrophthalazine core was demonstrated by its straightforward conversion to dihydro-phthalazines, phthalazines, or pyrazolo dione derivatives. Furthermore, the N-N bond was reduced to afford a new route to 1,4-diamines.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article