Efficient Synthesis of Cyclic β-Oxophosphoranes by Microwave-Assisted Reaction of Cyclic Phosphine Oxides and Dialkyl Acetylenedicarboxylates
作者:György Keglevich、Eszter Dudás、Melinda Sipos、Dóra Lengyel、Krisztina Ludányi
DOI:10.1055/s-2006-926395
日期:2006.4
The inverse Wittig-type reaction of a series of 2,4,6-trialkylphenyl cyclic phosphine oxides 3, 5, 7, 9, 11, 13, 15, 18 and 20 and dialkyl acetylenedicarboxylate giving β-oxophosphoranes 4, 6, 8, 10, 12, 14, 16, 19 and 21, respectively, can be accomplished in a convenient way under microwave conditions. At 150 °C, the MW-assisted reaction is more efficient and becomes 50-fold faster as compared to the thermal transformation. A further advantage is that the 2,5-dihydrophosphole moiety of the 2,4,6-triisopropylphenyl derivative 3 does not undergo double-bond rearrangement and that the 2,4,6-trimethylphenyl substrates 11 and 13, otherwise inactive in the reaction under discussion, could also be converted to β-oxophosphoranes 12 and 14. A series of new products 4Bb, 12, 14, 16b, 19 and 21 have been made available.
在微波条件下,一系列 2,4,6-三烷基苯基环状氧化膦 3、5、7、9、11、13、15、18 和 20 与乙炔二甲酸二烷基酯的逆维蒂希型反应可以方便地进行,并分别生成δ-氧膦 4、6、8、10、12、14、16、19 和 21。在 150 °C 的温度下,微波辅助反应的效率更高,比热转化快 50 倍。另一个优点是,2,4,6-三异丙基苯基衍生物 3 中的 2,5-二氢磷孔分子不会发生双键重排,而且 2,4,6-三甲基苯基底物 11 和 13 也可以转化为 δ-氧代磷烷 12 和 14。一系列新产品 4Bb、12、14、16b、19 和 21 已经问世。