Silicon-DirectedNazarov Reactions III. Stereochemical and Mechanistic Considerations
作者:Todd K. Jones、Scott E. Denmark
DOI:10.1002/hlca.19830660803
日期:1983.12.14
senses of electrocyclization are responsible for the observed products. Additional experiments suggest that steric, rather than stereoelectronic forces control the sense of cyclization. A qualitative description of the nature of reactive intermediates in the silicon-directed Nazarov reaction is proposed as well as an explanation for the remarkable efficacy of FeCl3 for inducing the reaction.
已经研究了远程取代基对硅定向纳扎罗夫反应中电环化的立体化学结果的影响。尽管立体控制度适中(约3:1),但主要异构体(4,5或7个取代的顺式-hexahydroind-2-en-1-ones)中的取代基始终对环融合中的质子而言是顺式的。彻底的光谱和构象分析表明,对电环化的不同感觉是所观察到的产物的原因。其他实验表明,空间力而不是立体电子力控制环化感。定性描述硅定向Nazarov中反应性中间体的性质提出了反应,并解释了FeCl 3诱导反应的显着功效。