A copper(I)-NHC-catalyzed annulation of 5-membered cyclic enols of furan, thiophene and indene family with 3-aryl-2H-azirines has been developed to provide a rapid access to furo[3,4-b]pyrrole, thieno[3,4-b]pyrrole, indeno[1,2-b]pyrrole derivatives. The reaction proceeds via a copper-initiated NC2 azirine bond cleavage with the retention of the CN double bond in the annulation product. The reaction
铜(I)-NHC催化的
呋喃,
噻吩和
茚家族的5-员环状烯醇与3-芳基-2 H-
叠氮基的环化反应可快速获得
呋喃[3,4- b ]
吡咯,
噻吩并[3,4- b ]
吡咯,
茚并[1,2- b ]
吡咯衍
生物。反应通过
铜引发的N C 2
叠氮键的裂解进行,同时在环化产物中保留C N双键。tetronic酸与3-芳基2 H-
叠氮基的反应也可以在无催化剂的条件下进行,方法是将烯醇两次添加到
叠氮基中,但是这种方法收率不高。这是所述N个的第一个例子Ç在不存在过渡
金属催化剂的情况下,在2个未取代的2 H-
叠氮基中发生2个键断裂。