title: Gallium Bromide-Promoted Dearomative Indole Insertion in 3-Indolylmethanols: Chemoselective and (Z/E)-Selective Synthesis of 3,3'-Bisindole Derivatives.
abstract: Gallium bromide (GaBr3)-promoted dearomative indole insertion in 3-indolylmethanols has been established, which chemoselectively constructs a biologically important 3,3'-bisindole framework bearing an all-carbon quaternary center in high yields and excellent (Z)-selectivities (up to 99% yield, all >95:5 Z/E). The reaction pathway was suggested to include a tandem sequence of Michael addition/C-C bond cleavage/nucleophilic addition, wherein the strong acidity of GaBr3played a crucial role in the key step of C-C bond cleavage. This reaction not only provides a new strategy for dearomatization of indoles, but also represents a new reaction category for 3-indolylmethanols, which involves a rarely reported late-stage C-C bond cleavage of 3-indolylmethanol derivatives. In addition, this approach also offers an efficient method for the synthesis of biologically important 3,3'-bisindole derivatives.
authors: School of Chemistry & Chemical Engineering, and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University , Xuzhou 221116, China.
authors: Cong-Shuai
authors: CS
authors: Wang
authors: School of Chemistry & Chemical Engineering, and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University , Xuzhou 221116, China.
authors: Tao
authors: T
authors: Fan
authors: School of Chemistry & Chemical Engineering, and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University , Xuzhou 221116, China.
authors: Hong-Hao
authors: HH
authors: Zhang
authors: School of Chemistry & Chemical Engineering, and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University , Xuzhou 221116, China.
authors: Can
authors: C
authors: Li
authors: School of Chemistry & Chemical Engineering, and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University , Xuzhou 221116, China.
authors: Yang
authors: Y
authors: Shen
authors: School of Chemistry & Chemical Engineering, and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University , Xuzhou 221116, China.
authors: Guang-Jian
authors: GJ
authors: Mei
authors: School of Chemistry & Chemical Engineering, and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University , Xuzhou 221116, China.
authors: Feng
authors: F
authors: Shi