352015-01-1Relevant articles and documents
Highly efficient chiral copper Schiff-base catalyst for asymmetric cyclopropanation of 2,5-dimethyl-2,4-hexadiene
Itagaki, Makoto,Hagiya, Koji,Kamitamari, Masashi,Masumoto, Katsuhisa,Suenobu, Katsuhiro,Yamamoto, Yohsuke
, p. 7835 - 7843 (2004)
A remarkable increase in catalytic activity is found for the asymmetric cyclopropanation of 2,5-dimethyl-2,4-hexadiene with diazoacetate by use of the chiral copper Schiff-base complexes, which are derived from substituted salicylaldehydes, chiral aminoalcohols, and copper acetate monohydrate. Furthermore, a combination of a chiral copper Schiff-base with a Lewis acid showed an increase in yield (up to 90%) and in enantioselectivity (up to 90% ee) for the asymmetric cyclopropanation of the diene with t-butyl diazoacetate at 20°C.