摘要:
N-Alkylated derivatives of (1R,2R)-(-)-pseudoephedrine and (1R,2S)-(-)-ephedrine afford, upon reaction with methanesulfonyl chloride, mixtures of 1-chloro- and 2-chloroamines which undergo stereospecific and regiospecific substitution reactions with sodium azide, amines, imides, thiols, thiolacetic acid, N-hydroxyphthalimide, and diphenylphosphine to give, in each case, a single isomeric product. These substitution reactions proceed with net retention of configuration. The procedure is not readily extended to nonbenzylic systems which give widely varying yields and regioisomeric ratios. The methodology provides for a facile synthesis of chiral diamines, triamines, aminohydroxylamines, aminothiols, aminosulfides, and aminophosphines from chiral 1,2-amino alcohols wherein either the amine or alcohol functionality is benzylic.