2094-03-3Relevant academic research and scientific papers
Photocatalytic Dehydrogenative Lactonization of 2-Arylbenzoic Acids
Ramirez, Nieves P.,Bosque, Irene,Gonzalez-Gomez, Jose C.
supporting information, p. 4550 - 4553 (2015/09/28)
A metal-free dehydrogenative lactonization of 2-arylbenzoic acids at room temperature was developed. This work illustrates the first application of visible-light photoredox catalysis in the preparation of benzo-3,4-coumarins, an important structural motif in bioactive molecules. The combination of photocatalyst [Acr+-Mes] with (NH4)2S2O8 as a terminal oxidant provides an economical and environmentally benign entry to different substituted benzocoumarins. Preliminary mechanistic studies suggest that this reaction most likely occurs through a homolytic aromatic substitution pathway.
Pd-catalyzed C-H lactonization for expedient synthesis of biaryl lactones and total synthesis of cannabinol
Li, Yan,Ding, Yan-Jun,Wang, Jian-Yong,Su, Yi-Ming,Wang, Xi-Sheng
supporting information, p. 2574 - 2577 (2013/07/11)
A practical Pd(II)/Pd(IV)-catalyzed carboxyl-directed C-H activation/C-O cyclization to construct biaryl lactones has been developed. The synthetic utility of this new reaction was demonstrated in an atom-economical and operationally convenient total synthesis of the natural product cannabinol from commercially available starting materials, with the newly developed method used for two key steps.
General and practical carboxyl-group-directed remote C-H oxygenation reactions of arenes
Wang, Yang,Gulevich, Anton V.,Gevorgyan, Vladimir
supporting information, p. 15836 - 15840 (2014/04/03)
Two methods for remote aromatic C-H oxygenation reactions, have been developed. Method1, the Cu-catalyzed oxygenation reaction, is highly efficient for cyclization of electron-neutral and electron-rich biaryl carboxylic acids into 3,4-benzocoumarins. Method2, the K2S2O 8-mediated oxygenation reaction, is more general and practical for cyclization of substrates with electron-donating and -withdrawing groups (see scheme). Copyright
