Synthesis of Pyrrole-Fused C,N-Cyclic Azomethine Imines and Pyrazolopyrrolopyrazines: Analysis of Their Aromaticity Using Nucleus-Independent Chemical Shifts Values
ORGANIC LETTERS, vol.18, no.3, pp.408-411, 2016 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 18 Issue: 3
- Publication Date: 2016
- Doi Number: 10.1021/acs.orglett.5b03434
- Journal Name: ORGANIC LETTERS
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.408-411
- Middle East Technical University Affiliated: Yes
Abstract
The AgOTf-catalyzed reaction of C-2 substituted pyrrole hydrazones having an N-propargyl group was studied. The selective 6-endo-dig mode of cyclization was observed, giving rise to the formation of pyrrole-fused C,N-cyclic azomethine imine derivatives. The reaction of one azomethine imine derivative with various dipolarophiles resulted in the formation of cycloadducts having a pyrazolopyrrolopyrazine skeleton. The aromaticity of C,N-cyclic azomethine imines as well as that of pyrazolopyrrolopyrazines was determined by calculating of nucleus-independent chemical shifts values.