Juanjuan Yang, Chunli Li, Zhihua Wang and Hua Wang Pages 706 - 710 ( 5 )
In this paper, an efficient synthesis of the two attractive fused thiophenes: helicene (1) and double helicene (2) bearing chiral chains was developed via multi-step moisture sensitive reactions in ca. 10.5 % and ca. 6.0 % isolated yields, respectively, with dithieno[2,3-b:3',2'-d]thiophene (7) as a starting material. However, 1 and 2 showed no optical rotations due to the too weak contribution from chiral induction of the chiral chain, (S)-3,7-dimethyl-octyl group in the formation of helicenes.
helicene, chiral chain, double helicene, thiophene-based, synthesis
Key Lab for Special Functional Materials of Ministry of Education, Henan University, Kaifeng, 475004, China.