Chemoenzymatic Synthesis of Pyrrolo[2,1-b]quinazolinones: Lipase-Catalyzed Resolution of Vasicinone
摘要:
A facile synthesis of bronchodilatory pyrrolo [2,1-b] quinazoline alkaloids by azidoreductive cyclization strategy employing TMSCl-NaI and bakers' yeast is described. Both the chemical and enzymatic methods are mild and take place at room temperature in good yields. Further, synthesis and resolution of vasicinone has been carried out by employing different lipases. It has been observed that lipase PS provides acetate of (S)-vasicinone in 98% ee.
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