| |
[摘要]：Using (R)-3-benzyl-4-phenyloxazolidine-2-thione (I) as model compd., a sequence of reactions has been established that allows the chiral auxiliary deprotection to furnish a primary amine. Treatment of I with Et triflate followed by ring opening with RbI and HI elimination with DBU, in a one pot process, gave S-Et N-benzyl-N-1-phenylvinylcarbamothioate (95% yield) which on acid hydrolysis and sapon. liberated benzylamine. A mechanistic study showed that the activated chiral oxazolidin-2-thione is a tunable intermediate towards the corresponding oxazolidin-2-one, thiazolidin-2-one, and thiazolidin-2-thione. All those reactions were chemoselective and preserved the chiral center. A structural anal. of this series of heterocycles, by NMR and X-ray diffraction, has been performed. |
|
