Base-Mediated Direct Transformation of N-Propargylamines into 2,3,5-Trisubstituted 1H-Pyrroles
摘要:
An efficient and base-mediated intramolecular cyclization of N-propargylamines for the synthesis of structurally diversified pyrroles in high yield has been described. The developed methodology is broadly applicable and is tolerated by a variety of functional groups. Key intermediates of natural product discoipyrrole C as well as HMG-CoA-reductase inhibitor have been successfully synthesized using developed chemistry. The proposed mechanism was supported by control experiments.
A Brønsted Acid Catalyzed Cascade Reaction for the Conversion of Indoles to α‐(3‐Indolyl) Ketones by Using 2‐Benzyloxy Aldehydes
作者:Ankush Banerjee、Modhu Sudan Maji
DOI:10.1002/chem.201902268
日期:2019.9.2
A Brønstedacid catalyzed, operationally simple, scalable route to several functionalized α-(3-indolyl) ketones has been developed and the long-standing regioisomeric issue has been eliminated by choosing appropriate carbonyls. A readily available and cheap bottle reagent was used as the catalyst. This protocol was also applicable to the synthesis of densely functionalized α-(3-pyrrolyl) ketones. A
The Dual Role of Ruthenium and Alkali Base Catalysts in Enabling a Conceptually New Shortcut to <i>N</i>-Unsubstituted Pyrroles through Unmasked α-Amino Aldehydes
A virtually salt-free and straightforward bimolecular assembly giving N-unsubstituted pyrroles through fully unmasked a-amino aldehydes, which was enabled by the dual effects of a catalytic ruthenium complex and an alkali metal base, is reported. Either solvent-free or acceptorless dehydrogenation facilitates high atom, step, and pot economy, which are otherwise difficult to achieve in multistep operations involving protection/deprotection.