摘要
以铜化合物催化重氮乙酸乙酯与2,5-二甲基-2,4-己二烯的环丙烷化反应,得到了高活性、高选择性的催化剂。探讨了催化剂结构与环丙烷化产率的关系,发现催化剂阴离子的吸电子能力、配体与铜(Ⅰ)的配位能力以及配体的空间位阻等对环丙烷化产率的影响有一定的规律性。
24 copper compounds including Cu(Ⅰ) and Cu(Ⅱ) salts and Cu(Ⅰ)-P complexes are used for catalyzing the cyclopropanation of ethyl diazoacetate with 2,5-dimethyl-2,4-hexadiene, and Cu(Ⅰ) Cu(Ⅱ) compounds which have excellent catalytic efficiency have been selected. It was found that the yield of chrysanthemrate, the monocyclopropanation product, depends upon the components of the catalyst used. When copper compounds which have different anions or ligands are used as the catalyst, the chrysanthemrate yields obtained have the following tendency:
CuX>CuPPh3X>CuP(OPh)3-Cu(PPh3)2Py-2- (SH)X (X=C1. Br. I)
CuLCl>CuLBr>CuLi (L is ligand)
Cu (O2CCC13) 2>Cu (O2CH2C1) 2>Cu (O2CCH3) 2
Usually, the stronger electron-withdrawing ability the anion has the weaker coordination ability the ligand has, the higher chrysanthemrate yield is obtained. When the size of the ligand is small, it does not affect the yield, but large ligand appears to be unfavorable to the reaction.
出处
《分子催化》
EI
CAS
CSCD
1992年第4期286-290,共5页
Journal of Molecular Catalysis(China)
关键词
重氮乙酸酯
铜
催化剂
菊酸酯
Diazoacetate, Copper catalyst, Cyclopropanation, Chrysanthemate.
