化学学报 ›› 2014, Vol. 72 ›› Issue (7): 815-819.DOI: 10.6023/A14060436 上一篇    下一篇

所属专题: 不对称催化与合成

研究通讯

手性膦烯配体在铑催化的芳基硼酸对β-芳基-α,β-不饱和磺酸酯不对称共轭加成反应中的应用

于月娜, 徐明华   

  1. 中国科学院上海药物研究所 上海 201203
  • 收稿日期:2014-06-04 出版日期:2014-07-14 发布日期:2014-06-26
  • 通讯作者: 徐明华 E-mail:xumh@simm.ac.cn
  • 基金资助:

    项目受国家自然科学基金(No.21325209)、上海市科委(No.14XD1404400)资助.

Chiral Phosphite-Olefin Ligands:Application in Rh-Catalyzed Asymmetric 1,4-Addition of Arylboronic Acids to β-Aryl-α,β-unsaturated Sulfonates

Yu Yue-Na, Xu Ming-Hua   

  1. Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203
  • Received:2014-06-04 Online:2014-07-14 Published:2014-06-26
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21325209), the Shanghai Municipal Committee of Science and Technology (No. 14XD1404400).

报道了手性膦烯配体在金属铑催化的芳基硼酸对β-芳基-αβ-不饱和磺酸酯不对称共轭加成中的应用. 经过系统的反应条件筛选和配体结构优化,发现含手性1,1'-联-2-萘酚骨架的膦烯配体L7与Rh(I)形成的催化剂可以高对映选择性地实现β-芳基-αβ-不饱和磺酸酯化合物的不对称1,4-加成反应. 此反应体系条件温和,底物普适性广,并取得了较高的收率(up to 95%)和优秀的对映选择性(up to 99% ee),为合成手性偕二芳基取代的磺酸酯类化合物提供了一种新方法.

关键词: 不对称催化, 膦烯配体, α,β-不饱和磺酸酯, 1,4-加成, 手性偕二芳基化合物

Chiral sulfonyl compounds have great versatility in organic synthesis, and they are also important as biologically active substances in medicinal chemistry. Among various methods developed for their synthesis, rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated sulfonyl compounds represents one of the most practical methods due to the stability and availability of the boronic acid used as a nucleophile. Although several Rh(I) complexes of bidentate ligands have been discovered for asymmetric conjugation addition of α,β-unsaturated sulfonyl compounds, some challenging issues still remain in terms of efficiency, enantioselectivity and substrate scope. Therefore, the development of an efficient catalytic system for the synthesis of chiral sulfonyl compounds is an important goal in extending the current methodology. Here, a general and mild method for the rhodium-catalyzed enantioselective catalytic conjugate addition of arylboronic acids to β-aryl-α,β-unsaturated sulfonate is described. The success of the process relies on the use of extraordinary simple chiral phosphite-olefin ligands as bidentate ligands which offer notable synthetic and economic advantages. Optimum reaction condition was determined to run the reaction at 50 ℃ using dioxane as the solvent, in the presence of 2.5 mol% of [Rh(coe)2Cl]2 and 5 mol% of chiral P/olefin ligand L7. This Rh(I) catalyst containing chiral P/olefin ligand has a broad substrate scope, a wide range of arylboronic acids with varying electronic and steric demands were successfully examined with α,β-unsaturated sulfonate (1). Notably, all transformations proceed efficiently to give the desired products in good yields (84%~95%) and excellent selectivities (92%~99% ee). The electronic properties of the arylboronic acids did not appear to affect the reactivity of the reaction. Besides, α,β-unsaturated sulfonate 1 with either an electron-donating or electron-withdrawing group on any aromatic carbon readily underwent the asymmetric arylation with arylboronic acids, affording chiral sulfonates in high yields and enantioselectivities. The current reaction provides a practical approach to the synthesis of diverse highly enantioenriched gem-diaryl substituted sulfonates.

Key words: asymmetric catalysis, P/olefin ligand, α,β-unsaturated sulfonate, 1,4-addition, chiral gem-diaryl compound