An unexpected reaction of 2-alkynylaryldiazonium tetrafluoroborate with sulfur dioxide.
An unexpected result from the reaction of 2-alkynylaryldiazonium tetrafluoroborate with sulfur dioxide is described. In the presence of morpholin-4-amine, this transformation catalyzed by copper(i) bromide proceeds through insertion of sulfur dioxide and intramolecular 5-endo cyclization, leading to benzo[b]thiophene 1,1-dioxides in moderate to good yields.
Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China. jie_wu@fudan.edu.cn.
Yong
Y
Luo
Xiaolin
X
Pan
Chen
C
Chen
Liangqing
L
Yao
Jie
J
Wu
D000588:Amines / Q000737:chemistry; D001881:Borates; D001888:Boric Acids / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D003500:Cyclization; D003979:Diazonium Compounds / Q000737:chemistry*; D008968:Molecular Conformation; D010087:Oxides / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry
D000588:Amines; D001881:Borates; D001888:Boric Acids; D001965:Bromides; D003979:Diazonium Compounds; D010087:Oxides; D013876:Thiophenes; C088015:benzothiophene; D013458:Sulfur Dioxide; C408079:cupric bromide; D003300:Copper; C098759:fluoroboric acid