Department of Chemistry, School of Chemical Sciences, Central University of Haryana, Mahendergarh, Haryana 123 029, India.
Department of Chemistry, University of Delhi, Delhi-110007, India.
Org Biomol Chem. 2020 Sep 23;18(36):7188-7192. doi: 10.1039/d0ob01623c.
Indoles, benzofurans and benzosultams endowed with arylsulfonyl groups were prepared in two steps from 2-bromoallyl sulfones. ortho-Halosulfonamides and ortho-iodophenol reacted with 2-bromoallyl sulfones in the presence of cesium carbonate to furnish products resulting from a formal vinylic substitution reaction. Palladium-catalyzed intramolecular Heck reaction of these adducts furnished sulfonylated indoles, benzosultams and benzofurans. Isomerization of the double bond participating in the Heck reaction under basic conditions led to the formation of two isomeric products in two cases. Conditions for selectively accessing each of the regioisomeric indoles were developed.
从 2-溴烯丙基砜出发，经两步反应合成了具有芳基磺酰基的吲哚、苯并呋喃和苯并噻唑啉。邻卤代磺酰胺和邻碘苯酚在碳酸铯存在下与 2-溴烯丙基砜反应，得到了通过形式乙烯基取代反应生成的产物。这些加成物的钯催化分子内 Heck 反应得到了磺化吲哚、苯并噻唑啉和苯并呋喃。在碱性条件下，Heck 反应中参与的双键发生异构化，在两种情况下生成了两种非对映异构体产物。开发了选择性获得每个区域异构体吲哚的条件。
