The intermolecular reaction of phenols with propiolicesters in TFA in the presence of a Pd(OAc)2 catalyst, affording coumarin derivatives, is described. An exclusive formation of 5,6,7-trimethoxy-...
A Convenient Solid-Phase Synthesis of Coumarins by TMSOTf-Catalyzed Intramolecular Seleno-Arylation of Tethered Alkenes
作者:E. Tang、Wen Li、Zhangyong Gao
DOI:10.1055/s-0031-1290618
日期:2012.4
performed using polystyrene-supported succinimidyl selenide as the selenium source. This catalytic process provides an efficient method for the regioselectivesynthesis of dihydrocoumarins possessing a seleno functionality, followed by syn elimination of selenoxides to provide coumarins in good yields and purities. Suzuki cross-coupling reaction of the resin-bound bromodihydrocoumarin was also performed
Synthesis of coumarins by Pt-catalyzed hydroarylation of propiolic acids with phenols
作者:Juzo Oyamada、Tsugio Kitamura
DOI:10.1016/j.tet.2006.04.080
日期:2006.7
Synthesis of coumarins from phenols and propiolicacids was examined by using a Pt catalyst such as PtCl2/AgOTf, K2PtCl4/AgOTf, and K2PtCl4/AgOAc. Propiolicacid reacted even with less reactive phenols in trifluoroacetic acid to give coumarins and dihydrocoumarins. In the case of substitutedpropiolicacids, phenylpropiolic acid and 2-octynoic acid, the reactions proceeded selectively to afford coumarins
Improved Synthesis of Coumarins by Iron(III)-Catalyzed Cascade Reaction of Propiolic Acids and Phenols
作者:Tsugio Kitamura、Md. Kutubi、Takuya Hashimoto
DOI:10.1055/s-0030-1258473
日期:2011.4
presence of FeCl3/AgOTf catalyst proceeded efficiently in a mixed solvent of trifluoroacetic acid and 1,2-dichloroethane, and provided coumarins in good to high yields. This iron-catalyzed reaction offers a much-improved synthesis of coumarins. iron - hydroarylation - coumarins - propiolic acids - propynoic acids - phenols
Pd-catalyzed chemo-selective mono-arylations and bis-arylations of functionalized 4-chlorocoumarins with triarylbismuths as threefold arylating reagents
作者:Maddali L.N. Rao、Abhijeet Kumar
DOI:10.1016/j.tet.2014.07.059
日期:2014.9
4-chlorocoumarins were studied under palladium catalysis usingtriarylbismuths as threefoldarylatingreagents. The high reactivity of 4-chlorocoumarins was demonstrated delivering mono- and bis-arylation products in a chemo-selective manner. The reaction conditions employed are simple, robust and the threefold coupling reactivity of triarylbismuthreagents was witnessed with good to high yields in 2–4 h conditions