One-Pot Allan-Robinson/Friedländer Route to Chromen-/Quinolin-4-ones through the Domino Acetylative Cyclisation of 2-Hydroxy-/2-Aminobenzaldehydes
作者:Vijai K. Rai、Fooleswar Verma、Ganeshwar P. Sahu、Manorama Singh、Ankita Rai
DOI:10.1002/ejoc.201701435
日期:2018.1.31
A domino reaction between 2‐hydroxy‐/2‐aminobenzaldehydes and α‐haloketones gives chromen‐4‐ones and quinolin‐4‐ones in good to excellent yields. This method represents a new extension of the Allan–Robinson and Friedländer reactions, and uses N‐heterocyclic‐carbene catalysis. This approach has the advantages of operational simplicity, ambient reaction conditions, and no by‐product formation.
Synthetic approach to flavanones and flavones via ligand-free palladium(ii)-catalyzed conjugate addition of arylboronic acids to chromones
作者:Donghee Kim、Kyungrok Ham、Sungwoo Hong
DOI:10.1039/c2ob26061a
日期:——
The remarkable catalytic effects of Fe(OTf)3 in the context of the Pd(II)-catalyzed conjugate addition of arylboronic acids to chromones were observed to yield a variety of flavanones under mild conditions. The addition of catalytic amounts of DDQ and KNO2 to the reactions exclusively yielded flavone analogs. The reaction scope for the transformation was fairly broad, affording good yields of a wide range of flavanones and flavones, which are privileged structures in many biologically active compounds.