The cyclization of nitrogen-centered radicals onto silyl enol ethers is an efficient method for the synthesis of polyhydroxylated alkaloids as the 2-hydroxymethylpyrrolidine core can be readily accessed from a linear precursor. During our studies on the synthesis of polyhydroxylated alkaloid CYB-3, we found that the diastereoselectivity of the cyclization was dependent on a complex combination of sterics
Synthesis of Bicyclic and Tricyclic Chiral Guanidinium Salts by an Intramolecular Alkylation Approach
作者:Aleksej Turočkin、William Raven、Philipp Selig
DOI:10.1002/ejoc.201601154
日期:2017.1.10
Synthetic studies leading to three new types of chiral guanidinium scaffolds are described. Structures of interest include bicyclic guanidine derivatives with various substitution patterns around the guanidine core, as well as a highly rigid tricyclic scaffold. The challenging targets were accessed by application of mercury(II)-promoted guanylation of N-Boc-substituted thioureas and Ishikawa's desulfurative
描述了导致三种新型手性胍支架的合成研究。感兴趣的结构包括在胍核心周围具有各种取代模式的双环胍衍生物,以及高度刚性的三环支架。通过应用汞 (II) 促进的 N-Boc 取代硫脲的鸟苷酸化和 Ishikawa 的脱硫环化来获得具有挑战性的目标。除了我们的合成逻辑之外,还介绍了三环胍盐的可扩展合成。
Cyclizations of Aminyl Radicals Generated from Substoichiometric Stannane
作者:Glenn Sammis、Huimin Zhai、Jason Wickenden
DOI:10.1055/s-0030-1259062
日期:2010.12
Substoichiometric amounts of tributyltin hydride were utilized in nitrogen-centered radical cyclizations onto silyl enol ethers for the formation of substituted cyclic imines.