American Chemical Society
jo049405i_si_001.cif (35.93 kB)

A Highly Stereoselective Synthesis of Optically Active Trisubstituted 1,2-Ethylenediamines:  The First Example of Grignard Addition to N-Diphenylphosphinoyl Ketimines Derived from Amino Acids

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posted on 2004-09-17, 00:00 authored by Yoshinori Kohmura, Toshiaki Mase
The efficient synthesis of optically active trisubstituted 1,2-ethylenediamines is described. Addition of aryl and/or alkyl Grignard reagents to α-amino N-diphenylphosphinoyl ketimines derived from α-amino acids was demonstrated to afford the desired trisubstituted 1,2-ethylenediamines in good yields and with high diastereoselectivities. Subsequent removal of the diphenyphosphinoyl group from the adduct was smoothly accomplished in reasonable yield without racemization under newly developed reductive conditions.