Chan CK, Chung YH, Wang CC. TMSOTf-mediated Kröhnke pyridine synthesis using HMDS as the nitrogen source under microwave irradiation.
RSC Adv 2022;
12:8263-8273. [PMID:
35424740 PMCID:
PMC8982443 DOI:
10.1039/d2ra00084a]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/01/2022] [Indexed: 01/20/2023] Open
Abstract
An efficient protocol for the preparation of pyridine skeletons has been successfully developed involving the TMSOTf/HMDS (trifluoromethanesulfonic acid/hexamethyldisilane) system for the intermolecular cyclization of chalcones under MW (microwave) irradiation conditions. This method provides a facile approach to synthesize 2,4,6-triaryl or 3-benzyl-2,4,6-triarylpyridines in good to excellent yields. Interestingly, the 2,6-diazabicyclo[2.2.2]oct-2-ene core was obtained by changing the acid additive to Sn(OTf)2, and the desired product was also confirmed using X-ray single-crystal diffraction analysis.
A Kröhnke pyridine synthetic route towards functionalized TAPs and 3-benzyl TAPs has been established using TMSOTf/HMDS under microwave irradiation conditions.![]()
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