When tertiaryamines 1 are reacted with perfluoro cis-2,3-dialkyloxaziridines 2 at −60°C corresponding N-oxides 3 are formed in high yields. The process is chemoselective and diastereoselective. The chemoselectivity in the reaction of alkenyl substituted pyridines is solvent dependent, attack occurring exclusively at the carbon-carbon double bond or at the nitrogen atom under protic and aprotic conditions
New Methodology for the N-Demethylation of Opiate Alkaloids
作者:Zemin Dong、Peter J. Scammells
DOI:10.1021/jo071171q
日期:2007.12.1
N-Demethylation is a key step in the preparation of a number of semisynthetic opiate pharmaceuticals. Herein we report a high-yielding, catalytic procedure for the N-demethylation of opiates which has a number of advantages over existing methods. For example, tetrasodium 5,10,15,20-tetra(4-sulfophenyl)porphyrinatoiron(II) (0.3 molar equiv) effected the transformation of codeine methyl ether to the corresponding N-nor analogue in 91% yield. The catalyst was readily removed and recycled.