10.1021/acs.orglett.7b02582.s002 Yuelei Gao Yuelei Gao Zhongyan Hu Zhongyan Hu Jinhuan Dong Jinhuan Dong Jun Liu Jun Liu Xianxiu Xu Xianxiu Xu Chemoselective Double Annulation of Two Different Isocyanides: Rapid Access to Trifluoromethylated Indole-Fused Heterocycles American Chemical Society 2017 atom-economic strategy acylaryl isocyanides 18 O-labeling experiment indole domino reaction Rapid Access chemoselective heterodimerization Trifluoromethylated Indole-Fused Heterocycles Chemoselective Double Annulation Isocyanide insertion Different Isocyanides α- trifluoromethylated isocyanides 2017-09-13 18:35:20 Dataset https://acs.figshare.com/articles/dataset/Chemoselective_Double_Annulation_of_Two_Different_Isocyanides_Rapid_Access_to_Trifluoromethylated_Indole-Fused_Heterocycles/5404606 An unprecedented chemoselective double annulation of α-trifluoromethylated isocyanides with <i>o</i>-acylaryl isocyanides has been developed. This new reaction provides a rapid, efficient, and complete atom-economic strategy for the synthesis of trifluoromethylated oxadiazino­[3,2-<i>a</i>]­indoles in a single operation from readily available starting materials. Isocyanide insertion into CO double bonds is disclosed for the first time as indicated by the results of <sup>18</sup>O-labeling experiment. A mechanism for this domino reaction is proposed involving chemoselective heterodimerization of two different isocyanides, followed by indole-2,3-epoxide formation and rearrangement.