...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Highly active rare-earth metal catalysts for heteroselective ring-opening polymerization of racemic lactide
【24h】

Highly active rare-earth metal catalysts for heteroselective ring-opening polymerization of racemic lactide

机译：用于外环形丙交酯的异质式开环聚合的高活性稀土金属催化剂

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

Rare-earth metal complexes usually exhibit high activities in the ring-opening polymerization (ROP) of lactide, yet only a few scandium complexes have shown satisfactory activity. Herein, we report the synthesis of a series of chiral anilido-oxazoline-supported scandium and yttrium complexes that exhibit high activity in the ROP of racemic lactide (rac-LA). Complexes La-f-Ln(CH2SiMe3)(2)THF (La-f = 2-(2,6-R2PhN)-phenyl- 4-(S)-R'-oxazoline; for 1a-f: L = La-f, Ln = Sc; for 2a-d: L = La-d, Ln = Y) were synthesized via the convenient one-pot reaction of Ln(CH2SiMe3)(3)(THF)(2) (Ln = Sc, Y) with the corresponding proligands. The crystal structures of 1a, 1d, 1e, and 1f were isostructural, adopting a distorted trigonal bipyramidal configuration. Sc complexes 1 showed outstanding activity in the ROP of rac-LA with heteroselectivity. TOFs of up to 720 h(-1) and 2910 h(-1) were obtained in THF at room temperature and toluene at 60 degrees C, respectively. To our knowledge, these are the highest activities reported for Sc systems. Y complexes 2 showed higher activity and heteroselectivity than the Sc complexes, with TOFs of up to 1176 h(-1) in THF at room temperature. Compared with the ortho-substituent on the anilido moiety, the bulky substituent at the chiral center of the oxazoline ring had a greater effect on controlling the heteroselectivity.
机译：稀土金属配合物通常在丙交酯的开环聚合（ROP）中表现出高活性，但只有少数钪配合物已经显示出令人满意的活性。在此，我们报告了一系列手性厌氧 - 恶唑啉钪和钇复合物的合成，其在外消旋丙交酯（RAC-LA）中表现出高活性。复合物La-F-LN（CH2Sime3）（2）THF（La-F = 2-（2,6-R2Phn） - 苯基-4-（S）-R'-恶唑啉;对于1A-F：L = La- F，Ln = Sc;对于2A-D：L = La-D，LN = Y）通过LN（CH2SIME3）（3）（3）（THF）（2）（LN = SC，Y. ）与相应的脯子。 1A，1D，1E和1F的晶体结构是表观的，采用扭曲的三角形双滤网构造。 SC复合物1在Rac-La的ROP中显示出具有异质切除的卓越活动。在60℃下，在室温和甲苯中，在THF中获得高达720小时（-1）和2910小时（-1）的TOF。为了我们的知识，这些是SC系统报告的最高活动。 Y络合物2显示出比SC复合物更高的活性和异质蚀刻，THF在室温下具有高达1176小时（-1）的TOF。与邻苯胺部分上的邻取代基相比，恶唑啉环的手性中心的庞大取代基对控制异质切除具有更大的影响。

著录项

  • 来源
  • 作者

    Pan Yu; Li Wenqiang; Wei Ning-Ning; So Yat-Ming; Lai Xiaoling; Li Yang; Jiang Kang; He Gaohong;

  • 作者单位

    Dalian Univ Technol State Key Lab Fine Chem Sch Petr &

    Chem Engn Panjin 124221 Peoples R China;

    Dalian Univ Technol State Key Lab Fine Chem Sch Petr &

    Chem Engn Panjin 124221 Peoples R China;

    Dalian Univ Technol Sch Life Sci &

    Med Panjin 124221 Peoples R China;

    Hong Kong Univ Sci &

    Technol Dept Chem Kowloon Clear Water Bay Hong Kong Peoples R China;

    Dalian Univ Technol State Key Lab Fine Chem Sch Petr &

    Chem Engn Panjin 124221 Peoples R China;

    Dalian Univ Technol State Key Lab Fine Chem Sch Petr &

    Chem Engn Panjin 124221 Peoples R China;

    Dalian Univ Technol State Key Lab Fine Chem Sch Petr &

    Chem Engn Panjin 124221 Peoples R China;

    Dalian Univ Technol State Key Lab Fine Chem Sch Petr &

    Chem Engn Panjin 124221 Peoples R China;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 化学;无机化学;
  • 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