• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of the American Chemical Society >Enantioselective Synthesis of Planar-Chiral Phosphaferrocenes by Molybdenum-Catalyzed Asymmetric Interannular Ring-Closing Metathesis
【24h】

Enantioselective Synthesis of Planar-Chiral Phosphaferrocenes by Molybdenum-Catalyzed Asymmetric Interannular Ring-Closing Metathesis

机译：钼催化不对称环间闭环易位合成手性平面二茂铁化合物

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Planar-chiral ferrocenesn1nare important chiral scaffolds and havenbeen utilized in various asymmetric reactions as ligandsn2nor catalystsn3nwith fair success. Recent entries to this class of compounds arenheterometallocenes such as azaferrocenes and phosphaferrocenes, andnthese Lewis basic organometallics have proven their usefulness innasymmetric synthesis.n2f,g,3b,cnStandard methods of obtaining nonra-ncemic planar-chiral ferrocenes are based either on resolution ofnracemates or on diastereoselective metalation using chiral directingngroupsn4nor external chiral bases.n5nTheir catalytic enantioselectivensynthesis is extremely rare,n5d,6,7nand further breakthroughs have beennclearly awaited. Recently, we and others reported the preparation ofnvarious bridged metallocenes by interannular ring-closing metathesis,n8nwhich have enabled us to modulate metallocenes by transition metalncatalysis. And thus, we are interested in controlling metallocene-basednplanar chirality using chiral metathesis catalysts. In spite of recentnadvances in asymmetric ring-closing metathesis (ARCM),n9nthe methodnhas been solely applied to the preparation of compounds with C-n9nornP-stereogenic10ncenters. After successful application of ARCM to thenkinetic resolution of racemic planar-chiral ferrocenes,n7a,bnwe reportnherewith catalytic enantioselective desymmetrization of planar-prochiralnphosphaferrocenes. The asymmetric reactions of the Lewis basicnsubstrates proceed very efficiently in the presence of an appropriatenchiral Mo-catalyst, and planar-chiral phosphaferrocenes are obtainednin high yields (vs 50% in kinetic resolutions) in up to 99% ee. This isnthe first application of ARCM to the induction of metallocene-basednplanar chirality. Indeed, this is the first example of asymmetric synthesisnof chiral molecules devoid of stereogenic centersn11nby ARCM.
机译：平面-手性二茂铁是重要的手性骨架，尚未在各种不对称反应中用作配体或催化剂，取得了成功。这类化合物的最新条目是杂金属茂金属，如氮杂二茂铁和磷二茂铁，这些路易斯碱性有机金属已证明它们在不对称合成中的有用性。使用手性方向基团n4或外部手性碱进行非对映选择性金属化。n5n其催化对映选择性合成极为罕见，n5d，6,7n尚待进一步突破。最近，我们和其他人报道了通过环间闭环易位反应制备各种桥联的茂金属，n8n使我们能够通过过渡金属催化来调节茂金属。因此，我们对使用手性复分解催化剂控制金属茂基的平面手性感兴趣。尽管最近出现了不对称闭环复分解反应（ARCM），但该方法仅用于制备具有C-n9nornP-stereogenic10n中心的化合物。在成功地将ARCM应用于外消旋的平面手性二茂铁的动力学拆分之后，n7a报道了平面前手性磷茂铁的催化对映选择性脱对称。 Lewis碱的底物的不对称反应在适当的支气管钼催化剂的存在下非常有效地进行，并且以高达99％ee的高收率（相对于动力学分辨率为50％）获得了平面手性磷二茂铁。这是ARCM在基于茂金属的平面手性诱导中的首次应用。的确，这是ARCM缺乏立体异构中心的手性分子不对称合成的第一个例子。

著录项

  • 来源
    《Journal of the American Chemical Society》 |2010年第7期|p.2136-2137|共2页
  • 作者

    Masamichi Ogasawara Susumu Watanabe Kiyohiko Nakajima and Tamotsu Takahashi;

  • 作者单位

    Catalysis Research Center and Graduate School of Life Science, Hokkaido Uni ersity, Kita-ku, Sapporo 001-0021,Japan, and Department of Chemistry, Aichi Uni ersity of Education, Igaya, Kariya, Aichi, 448-8542, Japan;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号