四炔的芳炔环加成反应简便合成芳胺

Simple Synthesis of Arylamines from Tetraynes via the Hexadehydro-Diels-Alder Reaction

芳胺作为一种合成砌块广泛存在于天然产物、医药品及分子材料中.诸如一些亲核芳香取代、亲电硝化还原、及过渡金属促进的氨基化合物芳基化作用等作为合成策略在Caryl—N键形成领域被长期应用.本工作在无金属催化条件下通过四炔的芳炔环加成(Hexadehydro-Diels-Alder,HDDA)反应高效合成了芳胺化合物.该反应特征表现在无金属催化、无添加剂、无氧化剂、无导向基团前体,反应在温和条件下高产率地得到炔官能化二环化合物并表现了优越的区域选择性.所合成产物的结构经各种波谱手段表征确证,其中化合物3h的结构还通过X射线单晶衍射分析确认.

Arylamines are widespread in natural products, pharmaceuticals and molecular materials, and are useful synthetic building blocks. From a synthetic standpoint, the formation of Caryl—N bonds has been achieved by classical methods such as nucleophilic aromatic substitution, electrophilic nitration/reduction, or the transition-metal-mediated arylation of amides. This paper describes an efficient method for the synthesis of arylamines by the hexadehydro-Diels-Alder（HDDA） reaction of tetraynes under catalyst-free condition. This process is achieved in the absence of metal catalyst, base or oxidant, and it does not require the pre-installation of directing groups. This reaction exhibited an excellent regioselectivity, producing highly substituted fused yne-functionalized bicyclic compounds under mild conditions with good to excellent yields. All new products were fully characterized by various spectroscopic techniques and high-resolution mass spectrometry. The molecular structure of 3h was confirmed using single-crystal X-ray analyses.