Homogeneous Catalysts Supported on Soluble Polymers: Biphasic Suzuki–Miyaura Coupling of Aryl Chlorides Using Phase-Tagged Palladium–Phosphine Catalysts
作者:Markus an der Heiden、Herbert Plenio
DOI:10.1002/chem.200305562
日期:2004.4.2
several cycles by means of polymeric Pd catalysts with soluble polyethylene glycol phase tags. Three sterically demanding and electron-rich phosphines 1-CH(2)Br,4-CH(2)P(1-Ad)(2)-C(6)H(4), and 2-PCy(2),2'-OH-biphenyl, and 2-PtBu(2),2'-OH-biphenyl were covalently bonded to 2000 Dalton MeOPEG-OH. The catalysts, which were formed in situ from Na(2)[PdCl(4)], the respective polymeric phosphine, KF/K(3)PO(4)
在双相条件下(DMSO /庚烷),芳基氯化物与PhB(OH)(2)的Suzuki-Miyaura偶联可通过具有可溶性聚乙二醇相标记的聚合物Pd催化剂,在几个周期内以几乎定量的产率进行。三个空间要求高且富含电子的膦1-CH(2)Br,4-CH(2)P(1-Ad)(2)-C(6)H(4)和2-PCy(2),2 '-OH-联苯和2-PtBu(2),2'-OH-联苯共价键合到2000道尔顿MeOPEG-OH。由Na(2)[PdCl(4)],相应的聚合膦,KF / K(3)PO(4)和PhB(OH)(2)原位形成的催化剂可在20℃有效地偶联芳基氯化物80℃,负载量为0.5 mol%,相应联苯衍生物的收率> 90%。极性相标签的使用通过简单地将含催化剂的DMSO溶液和含产物的正庚烷相进行相分离,可以有效地回收钯-膦催化剂。催化剂的高活性(TOF)在五个以上的反应循环中几乎保持不变,这涉及催化反应,产物