A new and efficient method for conjugate addition of trialkylphosphites to 3-acylsubstituted coumarins
作者:Rositca D. Nikolova、Anka G. Bojilova、Nestor A. Rodios
DOI:10.1016/j.tet.2004.08.069
日期:2004.11
A new and efficient conjugate addition of trialkylphosphites to 3-ω-bromoacetylcoumarin 1 catalysed by p-toluenesulfonic acid (TsOH) has been studied. Under the same conditions, an enolphosphate gave the corresponding esters of 3-acetyl-4-phosphono-2-oxochromans in high yields. The use of TsOH in the reaction of 3-acetyl-, 3-benzoyl-, and 3-ethoxycarbonyl coumarins led mainly to 1,4-addition products—the
Reaction of 3-bromobenzyl and 3-bromoacetyl coumarin with phosphites. Synthesis of some new phosphonates and phosphates in the coumarin series
作者:Rositca Nikolova、Anka Bojilova、Nestor A. Rodios
DOI:10.1016/s0040-4020(98)00892-8
日期:1998.11
3 with trialkyl phosphites afforded in good yields the corresponding dialkyl phosphonates 5, the Arbuzov reaction products. The interaction of trialkyl phosphites with 3-(ω-bromoacetyl)coumarin 4 gave the corresponding dialkyl vinylphosphates 8 as the only isolated products, whereas dialkylphosphites reacted with 4 under phase transfer catalysis and gave vinylphosphates 8 or dialkyl 1,2-epoxy-ethylphosphonates