Reversible P(III)/P(V) Redox: Catalytic Aza-Wittig Reaction for the Synthesis of 4(3<i>H</i>)-Quinazolinones and the Natural Product Vasicinone
作者:Long Wang、Ying Wang、Min Chen、Ming-Wu Ding
DOI:10.1002/adsc.201300950
日期:2014.3.24
The catalytic aza‐Wittig reaction based on a phosphine/phosphine oxide catalytic cycle is reported. The by‐product triphenylphosphine oxide (Ph3PO) was reduced in situ to triphenylphosphine (Ph3P) with good chemselectivity so that the aza‐Wittig reaction can be accomplished by using merely a catalytic amount of triphenylphosphine. The reaction has been demonstrated in an efficient synthesis of 4(3H)‐quinazolinones
报道了基于膦/氧化膦催化循环的催化氮杂-维蒂希反应。副产物三苯基膦氧化物(Ph 3 PO)以良好的化学选择性被原位还原为三苯基膦(Ph 3 P),因此仅使用催化量的三苯基膦即可完成氮杂-维蒂希反应。该反应已被证明在的4(3一种高效合成ħ)-quinazolinones和天然产物(小号)-vasicinone以高产率,通过使用三苯基膦(5%)的催化量和四甲基二硅氧烷/四异丙氧基钛[TMDS / Ti(Oi- Pr)4 ]还原剂系统(81–95%的收率和> 99%的ee)。