2012-2011
首页  科学研究  发表论文  2012-2011

Efficient Synthesis of 3,3'-Disubstituted Oxindoles Bearing α,β-Diamino Functionality via Catalytic Asymmetric Michael Additions of Oxindoles to Protected 2-Amino-1-Nitroethenes by Amino-Indanol(J. Org. Chem. 2011, 76, 4008–4017)

  

Graphic Abstract

  

We have developed the firstorganocatalytic methodology for the asymmetric Michael addition of 3-substrated oxindoles toprotected 2-amino-1-nitroethenes in the presence of a simple amino-indanol derivative. A wide spectrum of3,3'-disubstituted oxindoles bearingα,β-diamino functionality and vicinal quaternary/tertiary stereocenters were smoothly obtained in excellent yields (up to 99%), virtually perfect diastereoselectivities (up to >99:1) and good enantioselectivities (up to 90%). Two points particularly noteworthy in this work include: (1) this is the sole example so far for the asymmetric synthesis of 3,3'-disubstituted oxindoles bearingα,β-diamino functionality; and (2) the simple and readily available amino-indanol derivative1l works well for this kind of asymmetric Michael addition reaction, whereas some analogous organic bifunctional catalysts derived fromcinchona alkaloids or chiral 1,2-diamines are futile to control the enantioselectivity. In addition, the potential values of the catalyst system are also shown by gram-scale reaction and theversatile conversion of product. Working is ongoing to utilize the Michael adducts as a starting material for natural product synthesis in our laboratory.