Reductive conjugate addition nitro-Mannich route for the stereoselective synthesis of 1,2,3,4-tetrahydroquinoxalines
作者:James C. Anderson、Ian B. Campbell、Sebastien Campos、Iain H. Reid、Christopher D. Rundell、Jonathan Shannon、Graham J. Tizzard
DOI:10.1039/c6ob01530a
日期:——
structurally divergent synthesis of complex 1,2,3,4-tetrahydroquinoxalines with excellent diastereoselectivity is described. A wide array of nitroalkenes and imines derived from commercially available aromatic aldehydes and 2-chloroanalines were subjected to a key reductive conjugate addition nitro-Mannich reaction to give diastereomerically pure β-nitro amines. Sequential reduction of the nitro function
描述了具有优异的非对映选择性的复杂的1,2,3,4-四氢喹喔啉的简明,高收率和结构上不同的合成方法。对衍生自市售芳族醛和2-氯苯胺的多种硝基烯烃和亚胺进行关键的还原性共轭加成硝基-曼尼希反应,得到非对映体纯的β-硝基胺。硝基功能的顺序还原,然后是钯催化的分子内氮所得伯胺在2-氯苯胺上的芳基化反应得到高度取代的1,2,3,4-四氢喹喔啉。如果使用更强的酸甲磺酸促进反应,则发现非碱性亚胺可更好地参与硝基-曼尼希反应。3步反应序列对于药物如支架的阵列合成应该是有用的。