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Stereoselective Pinacol Coupling of Planar Chiral (arene) chromium Complexes ; Synthesis of Optically Pure 1,2-Dihetero Compounds

平面手性（芳烃）铬配合物的立体选择性频那醇偶联；

基本信息

批准号：
09640643
负责人：
UEMURA Motokazu
金额：
$ 2.11万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

Enantiomerically pure 1, 2-diols and diamines are important compounds as chiral ligand or auxiliary in asymmetric reaction. The reductive coupling of carbonyl compounds, pinacol coupling, is the most direct way to synthesize 1, 2-diols. Although this reaction can be achieved in high yield by lanthanoid metals or low valent transition metals, highly stereoselective formation of 1, 2-diols is problematic under conventional reductive coupling methods. (Arene)chromium complex can exist in two enantiomeric forms based on the planar chirality. We have investigated the pinacol coupling of planar chiral chromium complexes of benzaldehydes and benzaldiminesEnantiomerically pure (o-substituted benzaldehyde)Cr(CO)_3 complexes and (o-substituted benzaldimine)Cr(CO)_3 complexes were treated with samarium diiodide in THF to produce stereoselectively optically pure chromium-complexed threo-diols and diamines, respectively. These chromium-complexed threo-diols and diamines were oxidized to give the chromium free 1, 2-diols and diamines in enantiomerically pure form. Similarly, planar chiral (diene)Fe(CO)_3 and alpha-substituted ferrocencarboxaldehydes produced the corresponding enantiomerically pure 1, 2-diols in high yield.Furthermore, an intramolecular pinacol coupling of enantiomerically pure chromium complexes of axially chiral biphenyls having dicarbonyl, diimine and iminokarbonyl function afforded to trans 1,2-diols, diamines and aminoalcohols, respectively, under the same reaction conditions.

对映体纯的1，2-二醇和二胺是一类重要的手性配体或不对称反应助剂。羰基化合物的还原偶联，即频哪醇偶联，是合成1，2-二醇最直接的方法。虽然该反应可以通过镧系金属或低价过渡金属以高产率实现，但是在常规还原偶联方法下，1，2-二醇的高度立体选择性形成是有问题的。基于平面手性，（芳烃）铬配合物可以以两种对映体形式存在。本文研究了平面手性苯甲醛和苯甲醛亚胺铬配合物的频哪醇偶联反应。对映体纯的（邻取代苯甲醛）Cr（CO）_3配合物和（邻取代苯甲醛亚胺）Cr（CO）_3配合物在四氢呋喃中与二碘化钐反应，分别生成立体选择性光学纯的铬配合物苏式二醇和二胺。将这些铬络合的苏型二醇和二胺氧化，得到对映体纯形式的不含铬的1，2-二醇和二胺。同样地，平面手性（二烯）Fe（CO）_3与α-取代二茂铁甲醛也高产率地生成了相应的对映体纯的1，2-二醇，此外，在相同的反应条件下，具有二羰基、二亚胺和亚氨基羰基的轴向手性联苯的对映体纯的铬配合物的分子内片呐醇偶联分别生成了反式1，2-二醇、二胺和氨基醇.