Frontier Chemistry Center, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, 060-8628, Japan.
Chem Asian J. 2012 Oct;7(10):2446-9. doi: 10.1002/asia.201200481. Epub 2012 Jul 13.
A chiral O-linked C(2)-symmetric bidentate phosphoramidite (Me-BIPAM) was found to be efficient for the ruthenium-catalyzed addition of arylboronic acids to isatins. Asymmetric synthesis of 3-aryl-3-hydroxy-2-oxindoles by 1,2-addition of arylboronic acids to isatins was carried out in the presence of [RuCl(2)(PPh(3))(3)]/(R,R)-Me-BIPAM and KF, resulting in an enantioselectivity as high as 90 % ee. It was found that the reaction with N-protected isatins proceeds with high yields and good enantioselectivities. The best protective groups on the nitrogen atom were different depending on the substituents on the aromatic ring. The use of a N-benzyl group resulted in excellent enantioselectivities in many substrates compared with other groups.
一种手性 O-连接的 C(2)对称双齿膦酰胺配体（Me-BIPAM）被发现对芳基硼酸与色满酮的钌催化加成反应具有很高的催化活性。在[RuCl(2)(PPh(3))(3)]/(R,R)-Me-BIPAM 和 KF 的存在下，芳基硼酸与色满酮的 1,2-加成反应可以高对映选择性地进行，对映选择性高达 90%ee。研究发现，N-保护的色满酮与该反应具有很高的产率和良好的对映选择性。氮原子上的最佳保护基取决于芳环上的取代基，与其他基团相比，N-苄基在许多底物中表现出优异的对映选择性。
