Kirsch Stefan F, Overman Larry E, Watson Mary P
Department of Chemistry, 516 Rowland Hall, University of California, Irvine, California 92697-2025, USA.
J Org Chem. 2004 Nov 12;69(23):8101-4. doi: 10.1021/jo0487092.
Cobalt oxazoline palladacycles (COP) containing acetylacetonate and hexafluoroacetylacetonate ligands were prepared as catalysts for the asymmetric rearrangement of allylic trichloroacetimidates. These monomeric catalysts are more soluble than the previously described chloride-bridged dimer COP-Cl (1). COP-hfacac (2) provides rearranged allylic trichloroacetamides with high enantiomeric purities (91-98% ee) in solvents of widely varying polarities: cyclohexane, toluene, 1,2-dichloroethane, ethyl acetate, acetone, acetonitrile, and THF. The first single-crystal X-ray structure of a COP catalyst is also reported.
制备了含有乙酰丙酮和六氟乙酰丙酮配体的恶唑啉钴钯环（COP）作为烯丙基三氯乙酰亚胺不对称重排的催化剂。这些单体催化剂比先前描述的氯桥联二聚体COP-Cl（1）更易溶解。COP-hfacac（2）在极性差异很大的溶剂中：环己烷、甲苯、1,2-二氯乙烷、乙酸乙酯、丙酮、乙腈和四氢呋喃，能提供具有高对映体纯度（91-98% ee）的重排烯丙基三氯乙酰胺。还报道了COP催化剂的首个单晶X射线结构。
