Stereospecific Rearrangements during the Synthesis of Pyrrolidines and Related Heterocycles from Cyclizations of Amino Alcohols with Vinyl Sulfones
作者:Thomas G. Back、Masood Parvez、Huimin Zhai
DOI:10.1021/jo0350864
日期:2003.11.1
Conjugate additions of amino alcohols derived from alpha-amino acids to vinyl sulfones, followed by N-benzylation, chlorination, and intramolecular alkylation, provide a convenient route to substituted pyrrolidines. The process is accompanied by the stereospecific rearrangement of substituents from the alpha-position of the amine to the beta-position of the product and takes place via the corresponding
将衍生自α-氨基酸的氨基醇与乙烯基砜共轭加成,然后进行N-苄基化,氯化和分子内烷基化,为取代的吡咯烷提供了便利的途径。该过程伴随着取代基从胺的α-位置到产物的β-位置的立体有规重排,并通过相应的叠氮鎓离子中间体发生。在(2-哌啶)甲醇或2-(2-哌啶)乙醇与苯基反-1-丙烯基砜反应期间观察到另一种类型的重排,其中甲基似乎从β-迁移到α-砜部分的位置。该方法涉及通过将催化的苯亚磺酸根阴离子加成消除至前者乙烯基砜,然后将氨基共轭加成至后者砜,从而将苯基反-1-丙烯基砜异构化为苯基2-丙烯基砜。然后进行氯化和分子内烷基化,分别得到相应的重排的吲哚并立定和喹喔啉衍生物。