Scope and limitations of the nitro-Mannich reaction for the stereoselective synthesis of 1,2-diamines
Scope and limitations of the nitro-Mannich reaction for the stereoselective synthesis of 1,2-diamines
复制标题
DOI：
10.1021/jo048304h
复制
发表时间：
2005-01-21
影响因子：
3.6
通讯作者：
Wilson, C
中科院分区：
文献类型：
--
作者：
Anderson, JC;Blake, AJ;Wilson, C
在乙酸促进下，硝基丙酸锂与一系列芳香醛亚胺和脂肪醛亚胺的加成反应和刘易斯酸催化下[Sc-（OTf）（3），Cu（OTf）（2），或Ti（OiPr）（4）]与硝基丙酸三甲基硅酯的加成反应，得到了反富集（类似于3 -19：1）的β-硝基胺，产率> 95%。结果表明，在刘易斯酸催化的加成反应中，非极性的N-亚胺保护基对邻甲氧基苄基（OMB）的反应具有较好的选择性和产率.用SmI 2还原，用COCl 2处理，然后OMB脱保护，以55- 79%的总收率从亚胺得到非对映体纯的顺式咪唑烷酮。初步研究结果表明，乙酸作为溶剂，可以催化N-OMB-亚苄基胺与硝基丙烷的反应。以得到化学上更稳定的顺式-β-亚硝胺产物。
DIAGRAMThe acetic acid-promoted addition of lithium nitropropanate and the Lewis acid-catalyzed [Sc-(OTf)(3), Cu(OTf)(2), or Ti(OiPr)(4)] addition of trimethylsilyl nitropropanate to a rang of heteroaromatic and simple aliphatic aldimines gave anti-rich (similar to3-19:1) beta-nitroamines in > 95 % yields as the kinetic products. It was found that a nonpolar N-imine protecting group was essential for reactivity with the o-methoxybenzyl (OMB) group giving better selectivities and yields than p-methoxybenzyl (PMB) or p-methoxyphenyl (PMP) in the Lewis acid-catalyzed addition reactions. Reduction with SmI2, treatment with COCl2, followed by OMB deprotection gave diastereomerically pure cis-imidazolidinones in 55-79 % overall yield from imine. Preliminary results have shown that acetic acid can catalyze the reaction of N-OMB-benzylideneamine with nitropropane, used as solvent.. to give the thermodynamically more stable syn-beta-nitroamine product.