Facile synthesis of coumarin via the tandem reaction of salicylaldehyde with aryl-substituted 1,1-dibromo-1-alkene was developed. This new protocol proceeds smoothly under mild and transition-metal-free conditions, it allows rapid access to coumarins containing various heteroatoms that are more difficult to prepare by traditional methods. Based on the isolated intermediate of 4-(diethylamino)-3-phenylchroman-2-one and detailed mechanistic studies, a credible tandem pathway was proposed.
开发了一种简单的合成
香豆素的方法,利用
水杨醛与芳基取代的1,1-二
溴-1-烯的串联反应。该新方法在温和且无过渡
金属的条件下顺利进行,能够快速合成含有多种杂原子的
香豆素,而这些
香豆素通过传统方法更难制备。基于分离得到的中间体4-(二乙
氨基)-3-苯基克罗莫酮和详细的机理研究,提出了一条可信的串联反应路径。