Soluble polyisobutylene-supported reusable catalysts for olefin cyclopropanation Academic Article uri icon

abstract

  • Polyisobutylene oligomers (PIB) have been used as soluble supports for the immobilization of cyclopropanation catalysts. In addition to simple carboxylate ligands, chiral bisoxazolines have been successfully attached to these heptane-soluble polymers. Their use and recovery has been investigated using cyclopropanation of styrene as an example. An achiral PIB-bound Rh(II) catalyst showed good activity and could be easily recycled nine times using a liquid-liquid biphasic separation technique. PIB-supported bisoxazoline ligands for Cu(I) catalysts were also prepared. These chiral catalysts showed good catalytic activity and stereoselectivity. A chiral ligand prepared from phenylglycine provided the most effective stereocontrol and gave the trans- and cis-cyclopropanation products in 94% ee and 68% ee, respectively. All three PIB-bound chiral bisoxazoline-Cu(I) catalysts prepared could be reused five to six times. 2007 Elsevier Ltd. All rights reserved.

published proceedings

  • TETRAHEDRON LETTERS

author list (cited authors)

  • Bergbreiter, D. E., & Tian, J.

citation count

  • 32

complete list of authors

  • Bergbreiter, David E||Tian, Jianhua

publication date

  • June 2007