Salicylaldehyde based oxazolidines as catalysts for the asymmetric addition of diethylzinc to aldehydes
作者:Raleigh W. Parrott、Christopher G. Hamaker、Shawn R. Hitchcock
DOI:10.1002/jhet.5570450336
日期:2008.5
series of oxazolidines have been prepared by condensation of N-isopropyl norephedrine with a variety of salicylaldehyde derivatives. Despite the stereochemical relationship of (1R,2S)-norephedrine with (1R,2S)-ephedrine, the resultant oxazolidines 12-14 were determined to have a stronger stereochemical relationship with (1S,2S)-pseudoephedrine based oxazolidines. The resultant oxazolidines were used
通过使N-异丙基去氧麻黄碱与多种水杨醛衍生物缩合,制备了一系列的恶唑烷。尽管(1 R,2 S)-去氧麻黄碱与(1 R,2 S)-麻黄碱存在立体化学关系,但确定的恶唑烷12-14与基于(1 S,2 S)-伪麻黄碱的立体化学关系更强恶唑烷。在将二乙基锌添加到几种醛中后,将所得的恶唑烷用作催化配体。已确定恶唑烷衍生物12给出最高的产率和中等的对映选择性。