C2-Symmetric 1,2-Diamine/Copper(II) Trifluoromethanesulfonate Complexes as Chiral Ctalysts. Asymmetric Cyclopropanations of Styrene with Diazo Esters

Article abstract of DOI:10.1016/0040-4039(94)80029-4

Styrene and diazo esters react in the presence of copper(II) trifluoromethanesulfonate (1 molpercent) and (1S,2S)-N,N'-di(mesitylmethyl)-1,2-diphenyl-1,2-ethanediamine (2-3 molpercent) to give 2-phenyl-1-cyclopropanecarboxylates in good to excellent optical yields.This reaction has been applied to the synthesis of crythanthemic acid.