Facile one-pot synthetic access to libraries of diversely substituted 3-aryl (Alkyl)-coumarins using ionic liquid (IL) or conventional base/solvent, and an IL-mediated approach to novel coumarin-bearing diaryl-ethynes
摘要:
The in-situ formed carbonylimidazole derivatives of Ar(alkyl)-CH2COOH react at r.t. with substituted salicylaldehydes in [BMIM][PF6] or [BMIM] [BEd as solvent, and [PAIM][NTf (2)] as basic-IL to produce libraries of 3-aryl(alkyl)coumarins. Whereas these reactions can also be performed with similar efficiency in THF by employing DBU, the IL approach offers easier work-up and recycling of the IL solvent. An IL-mediated approach to the synthesis of novel coumarin-bearing diaryl-ethynes by the Sonogshira reaction is also reported, and the potential for recycling/reuse of the IL solvent is shown. (C) 2020 Elsevier Ltd. All rights reserved.
Pd-catalysed carbonylative annulation of salicylaldehydes with benzyl chlorides using<i>N</i>-formylsaccharin as a CO surrogate
作者:Vinod K. Yadav、Vishnu P. Srivastava、Lal Dhar S. Yadav
DOI:10.1039/c8nj03173h
日期:——
A highly efficient synthesis of 3-arylcoumarins by Pd-catalysed carbonylative cyclisation of salicylaldehydes with benzyl chlorides usingN-formylsaccharin as a CO source is developed.
dehydrogenative direct radical arylation of coumarins with arylboronicacids to afford 3-arylcoumarin derivatives is described. A similar reaction system is also applicable to the 3-arylation of quinolinone derivatives. These KMnO4/AcOH-mediated coupling reactions occur regioselectively at the C3 position of coumarins and quinolinones. Some notable features of this method are high efficiency, moderate
Synthesis of 3-arylcoumarins through N-heterocyclic carbene catalyzed condensation and annulation of 2-chloro-2-arylacetaldehydes with salicylaldehydes
作者:Yuansong Jiang、Wanzhi Chen、Weimin Lu
DOI:10.1016/j.tet.2013.03.025
日期:2013.5
The condensation reaction of 2-chloro-2-arylacetaldehyde with salicylaldehyde catalyzed by N-heterocyclic carbene (NHC) leading to 3-arylcoumarin was studied. A number of 3-arylcoumarin derivatives were obtained in good to excellent yields via this umpolung reaction. This reaction is facile and experimentally simple and mild.
Cute CO! An interesting and straightforward procedure for the carbonylativesynthesis of chromenonesfrom readily available salicylicaldehydes and benzylchlorides has been developed (see scheme; DPPP=1,3‐bis(diphenylphosphino)propane). In the presence of a palladium catalyst, various coumarins were produced in good to excellent yields.
Three-component coupling using arynes and DMF: straightforward access to coumarins via ortho-quinone methides
作者:Hiroto Yoshida、Yu Ito、Joji Ohshita
DOI:10.1039/c1cc11955a
日期:——
ortho-Quinone methides, arising from a formal [2+2] cycloaddition between arynes and DMF, were found to facilely undergo a [4+2] cycloaddition with ester enolates or ketenimine anions to produce diverse coumarins in a straightforward manner.