THE HIGHLY STEREOSELECTIVE CONVERSION OF N,N-DIMETHYLAMPHETAMINE INTO N-METHYLPSEUDOEPHEDRINE; A MIMIC OF THE ENZYME MEDIATED STEREOSPECIFIC BENZYLIC HYDROXYLATION OF 2-ARYLETHYLAMINES

Article abstract of DOI:10.1016/S0040-4020(01)90323-0

Treatment of (S)-(η⁶-N,N-dimethylamphetamine)Cr(CO)₃, with n-butyllithium below -40 deg C gives a stable benzylic carbanion via loss of the pro-R-benzylic proton.Warming of this anion above -40 deg C gives (η⁶-E-β-methylstyrene)Cr(CO), via an ElcB type elimination wilhst trapping with an electrophile below -40 deg C gives benzylically functionalised amphetamines with overall retention of configuration.The use of oxodiperoxymolybdenum(pyridine)hexamtehylphosphoramide as the electrophile gives optically pure (1S,2S)-N-methylpseudoephedrine after decomplexation.