Design of Pyrazolo-pyrrolo-pyrazines and Pyrazolo-pyrrolo-diazepines via AuCl3-Catalyzed and NaH-Supported Cyclization of N-Propargyl Pyrazoles
JOURNAL OF ORGANIC CHEMISTRY, vol.80, no.8, pp.3806-3814, 2015 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 80 Issue: 8
- Publication Date: 2015
- Doi Number: 10.1021/acs.joc.5b00034
- Journal Name: JOURNAL OF ORGANIC CHEMISTRY
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.3806-3814
- Middle East Technical University Affiliated: Yes
Abstract
A concise synthetic methodology for new heterocyclic scaffolds, such as pyrazolo-pyrrolo-pyrazine and pyrazolo-pyrrolo-diazepine skeletons, was developed. The key features of this method include (i) synthesis of pyrrole-derived alpha,beta-alkynyl ketones, (ii) introduction of various substituents into the alkyne functionality by Sonogashira cross-coupling, (iii) synthesis of pyrazole units by the reaction of alpha,beta-alkynyl compounds with hydrazine monohydrate, (iv) gold-catalyzed cyclization of pyrazoles with alkyne units, and (v) cyclization with NaH. Furthermore, this methodology allows various substituents to be introduced into all positions of the target compounds.