Catalyst-controlled chemoselective reaction of 3-indolylmethanols with cyclic enaminones leading to C2-functionalized indoles.

摘要: A catalyst-controlled chemoselective formal 1,2-addition of 3-indolylmethanols with cyclic enaminones has been established in the presence TfOH as a strong acid, which afforded C2-functionalized indole derivatives generally good yields (up to 89% yield). This reaction not only confronted great challenge but also provided strategy for C2-functionalization derivatives. The investigation on mechanism revealed that this included tandem sequence 1,4-addition/[1,3]-C migration/isomerization, [1,3]-C migration 1,4-addition product was key step and acidity catalyst played decisive role observed chemoselectivity.