Copper-catalyzed intramolecular cross dehydrogenative coupling approach to coumestans from 2′-hydroxyl-3-arylcoumarins
A copper-catalyzed intramolecular cross dehydrogenative C-O coupling reaction of 2′-hydroxyl-3-arylcoumarins was developed. This protocol provided a facile and efficient strategy for the construction of natural coumestans and derivatives in moderate to high yields. This transformation exhibited good functional group compatibility and was amenable to substrates with free phenolic hydroxyl groups.
O-heterocycles via laccase-catalyzed domino reactions with O2 as the oxidant
Laccase-catalyzed domino reactions of 4-hydroxy-6-methyl-2H-pyran-2-one or substituted 4-hydroxy-2H-chromen-2-ones with catechols using molecular oxygen as an oxidant afford coumestans and related O-heterocycles with yields ranging from 51% to 99%. Georg Thieme Verlag Stuttgart.
Synthesis and preliminary pharmacological evaluation of coumestans with different patterns of oxygenation
Five coumestans with different patterns of oxygenation in rings A and D were synthesized from resorcinol and aromatic aldehydes, and screened for their antimyotoxic activity. The most potent compound (2b, IC50 = 1 μM) was selected for study of
Da Silva, Alcides J.M.,Melo, Paulo A.,Silva, Noelson M.V.,Brito, Flavia V.,Buarque, Camilla D.,De Souza, Daniele V.,Rodrigues, Veronica P.,Pocas, Elisa S.C.,Noel, Francois,Albuquerque, Edson X.,Costa, Paulo R.R.
p. 283 - 286
(2007/10/03)
The first direct transformation of 2,2'-dihydroxychalcones into coumestans
Three coumestans, flemichapparin, medicagol and sophoracoumestan B, are synthesised by direct reaction of the analogous 2,2'-dihydroxychalcones with thallium (III) nitrate in methanol.
Kamara, B. Irene,Brandt, E. Vincent,Ferreira, Daneel
p. 861 - 868
(2007/10/03)
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