• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >New Benzo[h]quinoline-Based Ligands and their Pincer Ru and Os Complexes for Efficient Catalytic Transfer Hydrogenation of Carbonyl Compounds
【24h】

New Benzo[h]quinoline-Based Ligands and their Pincer Ru and Os Complexes for Efficient Catalytic Transfer Hydrogenation of Carbonyl Compounds

机译：新的基于苯并[h]喹啉的配体及其夹杂的Ru和Os配合物，用于羰基化合物的高效催化转移加氢

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

New benzo[h]quinoline ligands (HCN'N) containing a CHRNH2 (R = H (a), Me (b), tBu (c)) function in the 2-position were prepared starting from benzo[h]quinoline N-oxide (in the case of ligand a) and 2-chlorobenzo[h]quinoline (for ligands b and c). These compounds were used to prepare ruthenium and osmium complexes, which are excellent catalysts for the transfer hydrogenation (TH) of ketones. The reaction of a with [RUCl2- (PPh3)(3)] in 2-propanol at reflux afforded the terdentate CN'N complex [RuCl(CN'N)(PPh3)(2)] (1), whereas the complexes [RuCl(CN'N)(dppb)] (2-4; dppb=Ph2P(CH2)(4)PPh2) were obtained from [RuCl,(PPh3)(dppb)] with a-c, respectively. Employment of (R,S)-Josiphos, (S,R)-Josiphos*, (S,S)-Skewphos, and (S)-MeO-Biphep in combination with [RuCl2(PPh3)(3)] and ligand a gave the chiral derivatives [RuCl(CN'N)(PP)] (5-8). The osmium complex [OsCl(CN'N)(dppb)] (12) was prepared by treatment of [OsCl2(PPh3)(3)] with dppb and ligand a. Reaction of the chloride 2 and 12 with NaOiPr in 2-propanol/toluene afforded the hydride complexes [MH(CN'N)(dppb)] (M=Ru 10, Os 14), through elimination of acetone from [M(OiPr)(CN'N)(dppb)] (M=Ru 9, Os 13). The species 9 and 13 easily reacted with 4,4'-difluorobenzophenone, via 10 and 14, respectively, affording the corresponding isolable alkoxides [M(OR)(CN'N)(dppb)] (M=Ru 11, Os 15). The complexes [MX(CN'N)(P-2)] (1-15) (M= Ru, Os; X=Cl, H, OR; P=PPh3 and P-2=diphosphane) are efficient catalysts for the TH of carbonyl compounds with 2-propanol in the presence of NaOiPr (2mol%). Turnover frequency (TOF) values up to 1.8 x 10(6) h(-1) have been achieved using 0.02-0.001 mol % of catalyst. Much the same activity has been observed for the Ru-Cl, -H, -OR, and the Os-Cl derivatives, whereas the Os-H and Os-OR derivatives display significantly lower activity on account of their high oxygen sensitivity. The chiral Ru complexes 5-8 catalyze the asymmetric TH of methyl-aryl ketones with TOF approximate to 10(5) h(-1) at 60 degrees C, up to 97% enatiomeric excess (ee) and remarkably high productivity (0.005 mol % catalyst loading). High catalytic activity (TOF up to 2.2 x 10(5) h(-1)) and enantioselectivity (up to 98% ee) have also been achieved with the in-situ-generated catalysts prepared from [MCl2(PPh3)(3)], (S,R)-Josiphos or (S,R)-Josiphos*, and the benzo[h]quinoline ligands a-c.
机译：从苯并[h]喹啉N-开始，制备了在2-位含有CHRNH2（R = H（a），Me（b），tBu（c））功能的新苯并[h]喹啉配体（HCN'N）。氧化物（对于配体a）和2-氯苯并[h]喹啉（对于配体b和c）。这些化合物用于制备钌和络合物，它们是酮转移氢化（TH）的极佳催化剂。 a与[RUCl2-（PPh3）（3）]在2-丙醇中的反应在回流条件下提供了三齿CN'N络合物[RuCl（CN'N）（PPh3）（2）]（1），而络合物[ RuCl（CN'N）（dppb）]（2-4; dppb = Ph2P（CH2）（4）PPh2）分别是从[RuCl，（PPh3）（dppb）]用交流电获得的。 （R，S）-Josiphos，（S，R）-Josiphos *，（S，S）-Skewphos和（S）-MeO-Biphep与[RuCl2（PPh3）（3）]和配体a的结合使用得到手性衍生物[RuCl（CN'N）（PP）]（5-8）。通过用dppb和配体a处理[OsCl2（PPh3）（3）]制备prepared络合物[OsCl（CN'N）（dppb）]（12）。氯化物2和12与NaOiPr在2-丙醇/甲苯中的反应通过从[M（OiPr）中除去丙酮，得到氢化物络合物[MH（CN'N）（dppb）]（M = Ru 10，Os 14） （CN'N）（dppb）]（M = Ru 9，Os 13）。物质9和13分别容易地分别通过10和14与4,4'-二氟二苯甲酮反应，得到相应的可分离的醇盐[M（OR）（CN'N）（dppb）]（M = Ru 11，Os 15） 。配合物[MX（CN'N）（P-2）]（1-15）（M = Ru，Os; X = Cl，H，OR; P = PPh3和P-2 = diphosphane）是高效的催化剂在NaOiPr（2mol％）存在下，羰基化合物与2-丙醇的TH。使用0.02-0.001 mol％的催化剂可实现高达1.8 x 10（6）h（-1）的周转频率（TOF）值。对于Ru-Cl，-H，-OR和Os-Cl衍生物观察到了几乎相同的活性，而由于它们的高氧敏感性，Os-H和Os-OR衍生物显示出明显较低的活性。手性Ru配合物5-8催化甲基芳基酮的不对称TH，在60℃时TOF约为10（5）h（-1），对映体过量（ee）高达97％，且生产率极高（0.005 mol催化剂负载百分比）。用[MCl2（PPh3）（3）制得的原位生成的催化剂也获得了高催化活性（TOF高达2.2 x 10（5）h（-1））和对映选择性（高达98％ee）。 ]，（S，R）-Josiphos或（S，R）-Josiphos *和苯并[h]喹啉配体ac。

著录项

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