The factors that control the relative and absolute stereochemistry of 1,3-disubstituted and 1,2,3-trisubstituted tetrahydro-ß-carbolines formed via the Pictet-Spengler reaction are discussed. In particular, the stereochemical factors that lead to the predominance of cis-1,3-disubstituted products under conditions of kinetic control are presented, with the aid of X-ray crystallographic data on a number of compounds; methods for assigning relative stereochemistry on the basis of NMR data are given; the mechanism by which racemisation can occur during the Pictet-Spengler reaction has also been studied, and procedures for eliminating this problem are given.
|Number of pages||9|
|Journal||Journal of the Chemical Society, Perkin Transactions 1|
|Publication status||Published - 1993|