Synfacts 2008(8): 0883-0883  
DOI: 10.1055/s-2008-1077922
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart ˙ New York

One-Pot Cascade Reactions Catalyzed by Star Polymer Catalysts

Contributor(s): Yasuhiro Uozumi, Yoichi M. A. Yamada, Toshihiro Watanabe
Y. Chi, S. T. Scroggins, J. M. J. Fréchet*
University of California, Berkeley, USA
Further Information

Publication History

Publication Date:
23 July 2008 (online)

Significance

Non-interpenetrating two star polymer catalysts designed to mimic the site isolation characteristics of enzymes enabled a one-pot asymmetric cascade reaction. Thus, the one-pot nucleophilic addition of 2 to 1 and Michael addition of the resulting 3 to 4 were performed with a star polymer salt catalyst 6˙7 (20 mol%) [prepared from an acidic star polymer 6 and imidazolidinone (S,S)-7], a pyrrolidine star polymer (S)-8 (20 mol%), and a catechol mediator 9 (1 mol equiv) to give ( R,S )-5 in 89% yield with >99% ee and 96% de. The use of 10 or 11 in place of 6 or 8 under similar conditions did not give 5.