Bidentate carbenoid ester coordination in ruthenium(ii) Schiff-base complexes leading to excellent levels of diastereo- and enantioselectivity in catalytic alkene cyclopropanationElectronic supplementary information (ESI) available: experimental and theoretical details, structures of [RuL1(CH3CN)2] and [RuL1(η2-CHCO2Et)] (.pdb). CCDC 167600. See http://www.rsc.org/suppdata/cc/b1/b104964j/

Abstract

Exceptionally high stereoselectivity (ee ⩽ 98%, dr ⩽ 99∶1) in the cyclopropanation of alkenes with ethyl diazoacetate using a non-planar ruthenium(II) Schiff-base precatalyst is a result of η²C,O binding of the carbenoid ester intermediate, according to DFT calculations.