title: Synthesis of dithieno[2,3-b:4',3'-d]siloles and their selective bromination.
abstract: The efficient synthesis of novel unsymmetrical dithienosiloles, 7,7-dimethyl-4,6-di(trimethylsilyl)-dithieno[2,3-b:4',3'-d]silole (1) and 7,7-dimethyl-2,4,6-tri(trimethylsilyl)-dithieno[2,3-b:4',3'-d]silole (2) has been developed by intramolecular silole formation with 4,4'-dibromo-2,2',5,5'-tetrakis(trimethylsilyl)-[3,3']bithienyl (3) as the starting material in the presence of t-BuLi. Upon treatment with N-bromosuccinimide (NBS) under controlled conditions, dithieno[2,3-b:4',3'-d]silole was selectively brominated to produce mono-, di-, and tribrominated dithieno[2,3-b:4',3'-d]siloles in good yields. The crystal structures of the title compounds are described.
authors.affiliation: Key Lab for Special Functional Materials of Ministry of Education, Henan University, Kaifeng, 475004, China.
authors.forename: Jincan
authors.initials: J
authors.lastname: Zhao
authors.forename: Dongfang
authors.initials: D
authors.lastname: Qiu
authors.forename: Jianwu
authors.initials: J
authors.lastname: Shi
authors.forename: Hua
authors.initials: H
authors.lastname: Wang