Synfacts 2011(4): 0453-0453  
DOI: 10.1055/s-0030-1259743
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart ˙ New York

Asymmetric Cyclopropanation with [Cu(OTf)2(t-Bu2-DABox)][Pt]@Si

Contributor(s): Yasuhiro Uozumi, Tsubasa Muto
Y. Motoyama, T. Nishikata, H. Nagashima*
Kyushu University, Kasuga, Japan
Further Information

Publication History

Publication Date:
18 March 2011 (online)

Significance

A polysiloxane gel immobilized Cu(OTf)2/(S,S)-t-Bu2-DABox complex was prepared by treatment of polymethylhydrosilane (1) with (S,S)-t-Bu2-DABox (2) and 1,5-hexadiene in the presence of Karstedt’s catalyst (eq. 1). The immobilized complex [Cu(OTf)2(t-Bu2-DABox)][Pt]@Si catalyzed the asymmetric cyclopropanation of alkenes 3 with l-menthyl diazoacetate (4) to give the corresponding products 5 in up to 98% yield with up to 96% de (trans isomer) (6 examples, eq. 2).