Multicomponent Annulative SO₂ Insertion of Heteroatom-Linked 1,7-Diynes for Accessing Tricyclic Sulfones

Lu Wang,¹ Yi-Ting Shen,¹ Yu-Xin Wang, Hai-Ying Wang,* Wen-Juan Hao,* Bo Jiang*

A metal-free radical multicomponent bicyclization of heteroatom-linked 1,7-diynes with aryl diazonium tetrafluoroborates and DABCO-bis(sulfurdioxide) (DABSO) is reported, enabling annulative SO₂ insertion access to produce two types of skeletally diverse tricyclic sulfones, namely, thieno[3,4-c]quinoline 2,2-dioxides and thieno[3,4-c]chromene 2,2-dioxides, with moderate to good yields by simply tuning the linkers of the 1,7-diynes. This protocol demonstrates remarkable compatibility regarding N- and O-linked 1,7-diynes with different substitution patterns and aryl diazonium tetrafluoroborates.

Adv. Synth. Catal. 2023, 365, 1693-1698; DOI: 10.1002/adsc.202300272