3782-00-1Relevant articles and documents
Rhodium-Catalyzed Intermolecular Cyclopropanation of Benzofurans, Indoles, and Alkenes via Cyclopropene Ring Opening
Jeyaseelan, Rubaishan,Lautens, Mark,Ross, Rachel J.
, (2020/06/29)
The generation of metal carbenoids via ring opening of cyclopropenes by transition metals offers a simple entry into highly reactive intermediates. Herein, we describe a diastereoselective intermolecular rhodium-catalyzed cyclopropanation of heterocycles and alkenes using cyclopropenes as carbene precursors with a low loading of a commercially available rhodium catalyst. The reported method is scalable and could be performed with catalyst loadings as low as 0.2 mol %, with no impact to the reaction yield or selectivity.
Titanium tetrachloride promoted cyclodehydration of aryloxyketones: Facile synthesis of benzofurans and naphthofurans with high regioselectivity
Zhang, Qiu,Luo, Juan,Wang, Bingqiao,Xiao, Xiaoqin,Gan, Zongjie,Tang, Qiang
, p. 1337 - 1340 (2019/04/16)
An efficient and facile method for the synthesis of a broad series of benzofurans and naphthofurans is described. The direct intramolecular cyclodehydration of aryloxyketones in the presence of titanium tetrachloride affords the corresponding benzofurans and naphthofurans with good regioselectivity and yields.
One-step regioselective synthesis of benzofurans from phenols and α-Haloketones
Wang, Bingqiao,Zhang, Qiu,Luo, Juan,Gan, Zongjie,Jiang, Wengao,Tang, Qiang
, (2019/06/21)
Reported here is the direct synthesis of naphthofurans and benzofurans from readily available phenols and α-haloketones promoted by titanium tetrachloride which combines Friedel-Crafts-like alkylation and intramolecular cyclodehydration into one step. This simple protocol allows for the formation of a variety of high value naphthofurans and benzofurans within which a series of cyclic and acyclic groups are readily incorporated. This process demonstrates the advantages of high levels of regioselectivity, broad substrate scope, and moderate to excellent yields.
