Organocatalytic condensation–ring opening–annulation cascade reactions between N-Bocindolin-2-ones/benzofuran-2(3H)-ones and salicylaldehydes for synthesis of 3-arylcoumarins
作者:Yuyu Cheng、Pengfei Zhang、Yanwen Jia、Zhiqiang Fang、Pengfei Li
DOI:10.1039/c7ob01730h
日期:——
An organocatalytic cascade synthesis of 3-arylcoumarins has been developed.
Copper-mediated synthesis of coumestans via C(sp 2 )-H functionalization: Protective group free route to coumestrol and 4′- O -methylcoumestrol
作者:Mayuri M. Naik、Vijayendra P. Kamat、Santosh G. Tilve
DOI:10.1016/j.tet.2017.07.057
日期:2017.9
A simple and efficient two step synthesis of coumestans is described. The key reaction in the synthesis is the use of easily available Cu(OAc)2 for CH functionalization of 3-(2-hydroxyphenyl)coumarin to give coumestan ring system via formal oxidative cyclization. This approach provided a short protective group free route to naturallyoccurring coumestrol and 4′-O-methylcoumestrol.
A series of 6-halo-3-hydroxyphenylcoumarins (resveratrol-coumarins hybrid derivatives) was synthesized in good yields by a Perkin reaction followed by hydrolysis. The new compounds were evaluated for their vasorelaxant activity in intact rat aorta rings pre-contracted with phenylephrine (PE), as well as for their inhibitory effects on platelet aggregation induced by thrombin in washed human platelets. These compounds concentration-dependently relaxed vascular smooth muscle and some of them showed a platelet antiaggregatory activity that was up to thirty times higher than that shown by trans-resveratrol and some other previously synthesized derivatives.