在汞灯下由3-碘黄酮生成乙烯基自由基,并且与五元杂芳烃发生串联环化反应,需要两个连续的CC键形成,以合成苯并[ e ] chromeno [2,3 - g ]吲哚-13(1 H))-一阶导数。串联环化反应在乙腈中进行,没有任何添加剂,例如过渡金属,配体和氧化剂,在温和且环境友好的反应条件下,以高收率产生了各种各样的新型多环x吨酮骨架。
A regioselective approach for construction of 5-membered and 6-membered flavonoid is established by Pd catalyzed carbonylative cyclization of 2-iodophenol with terminal alkynes using different amine bases under mild reaction condition. The catalytic experiments found that piperazine preferentially accelerate 6-endo cyclization, and triethylamine mediated Pd catalyzed 5-exo cyclization. Under optimized
Pd(OAc)<sub>2</sub>/SPPh<sub>3</sub> accelerated activation of gem-dichloroalkenes for the construction of 3-arylchromones
作者:Jianming Liu、Weiwei Song、Yuanyuan Yue、Ren Liu、Hong Yi、Kelei Zhuo、Aiwen Lei
DOI:10.1039/c5cc06334e
日期:——
The Pd-catalyzed regioselective intramolecular nucleophilic substitution of gem-dichloroalkene derivatives with salicylaldehydes leading to the synthesis of 3-arylchromones has been developed.
cleavage/intramolecular 6-endo-dig annulation/hydrocarbonylation for the synthesis of the valuable 2-aryl-4H-chromen-4-ones is described. This practical synthesis strategy utilizes propargylamines and air as the oxygen source and green carbonylation reagent, in which propargylamines are activated by the inexpensive and available dimethyl 2,2′-azobis(2-methylpropionate) (AIBME) and (PhSe)2 as the radical initiators
A convenient procedure for converting aryl alcohols to aryl fluorides via aryl nonafluorobutylsulfonates (ArONf) is presented. Moderate to good one-pot, two-step yields were achieved by this nonaflation and microwave-assisted, palladium-catalyzed fluorination sequence. The reductive elimination step was investigated by DFT calculations to compare fluorination with chlorination, proving a larger thermodynamic driving force for the aryl fluoride product. Finally, a key aryl fluoride intermediate for the synthesis of a potent HCV NS3 protease inhibitor was smoothly prepared with the novel protocol.