Neutral aminyl radicals generated by anodic oxidation of lithium alkenylamides 2 undergo a stereoselectivecyclization to give -1-methyl-2,5-disubstituted pyrrolidines 4. Their stereochemistry was confirmed by a comparison with -1,2-dimethyl-5-phenylpyrrolidine, the structure of which was established by X-ray crystallographic analysis of its quarternary ammonium bromide 6.
Control of the Stereoselectivity in the Synthesis of 1-Methyl-2,5-disubstituted Pyrrolidines by Mercury(II)-initiated Cyclization of Substituted Alk-4-enylamines
作者:Masao Tokuda、Yasufumi Yamada、Hiroshi Suginome
DOI:10.1246/cl.1988.1289
日期:1988.8.5
The stereoselectivity in the synthesis of cis- and trans-1-methyl-2,5-disubstituted pyrrolidines by mercury(II)-initiated cyclization of substituted alk-4-enylamines can be controlled by choosing the appropriate mercury salt and solvent.
可以通过选择合适的汞盐和溶剂来控制通过汞 (II) 引发的取代 alk-4-enylamines 环化合成顺式和反式 1-甲基-2,5-二取代吡咯烷的立体选择性。
Stereoselective cyclization of δ-alkenylamines catalyzed with butyllithium. Synthesis of cis-N-methyl-2,5-disubstituted pyrrolidines
Treatment of δ-alkenylamines (1a-1d) with a catalytic amount of butyllithium gave cis-N-methyl-2,5-disubstituted pyrrolidines (2a-2d) stereoselectively in good yields.
NMR evidence of the kinetic and thermodynamic products in the NIS promoted cyclization of 1-phenyl-4-pentenylamines. Synthesis and reactivity of trans-2-phenyl-5-iodopiperidines
作者:Faïza Diaba、Josep Bonjoch
DOI:10.1039/c0cc05105e
日期:——
The intramolecular reaction of secondary amines with tethered alkenes using NIS was studied, which gave insight into the kineticvs. thermodynamiccontrol of the iodoaminocyclization and the regioselectivity of the aziridinium ring-opening reactions, and led to functionalized piperidines.