Novel rutheniumcomplexes with anionicphosphine ligands were found to be efficient in the catalytic cyclopropanation reaction of olefins with ethyl diazoacetate.
The system hexafluoroisopropanol/ethyl diazoacetate/Cu(OTf)2 is efficient for the cyclopropanation reaction. The process is experimentally simple, and efficient with various olefins in particular terminal, disubstituted double bonds.
Olefin cyclopropanation catalysed by novel ruthenium-arene complexes containing phosphines with pendent arenes
作者:François Simal、Dominique Jan、Albert Demonceau、Alfred F. Noels
DOI:10.1016/s0040-4039(99)00057-x
日期:1999.2
Ruthenium-arene complexes containing phosphines with pendent aryl groups [RuCl2(eta(6)-p-cymene)(PCy2(CH2)(3)Ar)]. Ar = C6H5 and 3,5-(CH3)(2)-C6H3 (1 and 3), and the resulting chelating complexes [RuCl2(PCy2(CH2)(3)-eta(6)-Ar)] (2 and 4) mediate the cyclopropanation of olefins with ethyl diazoacetate. Comparison of the reactivity patterns of these complexes indicates that p-cymene disengagement is likely the key step in the reactions catalysed by non-chelating complexes 1 and 3. (C) 1999 Elsevier Science Ltd. All rights reserved.