New catalytic system Cu(OAc)2—2,4-lutidine—ZnCl2 for olefin cyclopropanation with methyl diazoacetate

Abstract

A new efficient catalytic system consisting of Cu(OAc) 2 , 2,4 lutidine, and ZnCl 2 was found for the cyclopropanation of unsaturated compounds with methyl diazoacetate. In the case of conjugated dienes, the process occurs regioselectively at the most alkylated C=C bond.

Copper-Catalyzed Regiospecific and 1,2-Regioselective Cyclopropanation of (1Z)-1-Amino- and (1Z)-1-Oxy-1,3-butadienyl Derivatives

“…Gareev et al reported one example of the 1,2-regioselective cyclopropanation of (Z)-1-methyl-1,3-butadiene (1,3-pentadiene) to give the corresponding vinylcyclopropane derivative. 6 The Z ge-ometry reduces the steric repulsion of the double bond, and the rate of 1,2-addition would be improved. 5 However, the study of the 1,2-regioselective cyclopropanation of 1-substituted 1,3-butadienyl derivatives has never advanced very far because of the difficulty of preparing (1Z)-1-substituted 1,3-butadienyl derivatives.…”

Cu(OAc)2-2,4-Lut-ZnCl2 – Efficient Catalyst of Functionalization of Isobutylene Oligomers and 1,2-Polybutadiene with Methyldiazoacetate

“…It should be noticed that the Cu(OAc) 2 -2,4-Lut-ZnCl 2 catalytic system in this interaction shows an activity comparable with that in reactions of cyclopropanation of terminal monoolefins (hexane-1) and 1,3-dienes with methyldiazoacetate. Increasing of a carbon chain length leads to decreasing of target ethers yields [8].…”