Visible-light synthesis of 4-substituted-chroman-2-ones and 2-substituted-chroman-4-ones <i>via</i> doubly decarboxylative Giese reaction
作者:Marek Moczulski、Ewelina Kowalska、Elżbieta Kuśmierek、Łukasz Albrecht、Anna Albrecht
DOI:10.1039/d1ra05914a
日期:——
Doubly decarboxylative, photoredox synthesis of 4-substituted-chroman-2-ones and 2-substituted-chroman-4-ones is described. The reaction involves two independent decarboxylation processes: the first one initiating the cycle and the second completing the process. Visible light, photoredox catalyst, base, anhydrous solvent and inert atmosphere constitute the key parameters for the success of the developed
Photoredox Functionalization of 3-Halogenchromones, 3-Formylchromones, and Chromone-3-carboxylic Acids: Routes to 3-Acylchromones
作者:Satenik Mkrtchyan、Viktor O. Iaroshenko
DOI:10.1021/acs.joc.0c00537
日期:2020.6.5
describes a set of new and efficient syntheticroutes toward 3-acyl-substituted chromones ranging from readily available chromone precursors, namely 3-halogenchromones, 3-formylchromones, and chromone-3-carboxylic acids by means of visible-light photoredox catalysis. The operationally simple protocols transform a wide variety of chromone derivatives into challenging 3-acyl-substituted chromones in excellent
Decarboxylative Aminocatalytic Cascade for the Synthesis of Dihydroxanthones
作者:Anna Albrecht、Jan Bojanowski
DOI:10.1002/adsc.201700400
日期:2017.9.4
A novel decarboxylativeaminocatalytic strategy for the synthesis of 4,4a‐dihydroxanthones is described. It was realized by employing dienamine activation and utilizes readily available β,β‐disubstituted enals and chromone‐3‐carboxylic acids as starting materials. A decarboxylation reaction is the key step of the cascade making the aminocatalyst turnover possible.
Doubly Decarboxylative Synthesis of 4-(Pyridylmethyl)chroman-2-ones and 2-(Pyridylmethyl)chroman-4-ones under Mild Reaction Conditions
作者:Jan Bojanowski、Anna Albrecht
DOI:10.3390/molecules26154689
日期:——
The doubly decarboxylative Michael–type addition of pyridylacetic acid to chromone-3-carboxylic acids or coumarin-3-carboxylic acids has been developed. This protocol has been realized under Brønsted base catalysis, providing biologically interesting 4-(pyridylmethyl)chroman-2-ones and 2-(pyridylmethyl)chroman-4-ones in good or very good yields. The decarboxylative reaction pathway has been confirmed
A new methodology was developed for the highly efficient one-pot multicomponent synthesis of chromanone-based 3,3′-pyrrolidinyl-spirooxindoles via a 1,3-dipolarcycloaddition reaction of chromones 1 with azomethine ylides (thermally generated in situ from isatins and proline or thioproline). Another valuable application of this method was for the less reactive chromone through a carboxylic acid-activation