Domino CN Coupling/Annulation versus CN Coupling/ Hydroamination of 2-Alkynyl-3-bromobenzothiophenes and 2-Alkynyl-3-bromothiophenes. Highly Efficient Synthesis of Benzothieno[3,2-b]quinolines and Thieno[3,2-b]pyrroles
作者:Ghazwan Ali Salman、Munawar Hussain、Viktor Iaroshenko、Alexander Villinger、Peter Langer
DOI:10.1002/adsc.201000709
日期:2011.2.11
palladium-catalyzed reaction of 2-alkynyl-3-bromothiophenes with anilines afforded thienopyrroles by a domino CN coupling/hydroamination process, the reaction of 2-alkynyl-3-bromobenzothiophenes with anilines resulted, under identical conditions, in the formation of benzothienoquinolines by a domino CN coupling/annulation process. The electronic character of the aniline also has an influence on the product distribution
Pd-Catalyzed Cascade Crossover Annulation of <i>o</i>-Alkynylarylhalides and Diarylacetylenes Leading to Dibenzo[<i>a</i>,<i>e</i>]pentalenes
作者:Jian Zhao、Kazuaki Oniwa、Naoki Asao、Yoshinori Yamamoto、Tienan Jin
DOI:10.1021/ja403382d
日期:2013.7.17
A novel and selective Pd-catalyzed cascade crossover-annulation of o-alkynylarylhalides and diarylacetylenes for the synthesis of dibenzo[a,e]pentalenes has been reported. Various arylacetylenes with a wide range of functional groups were tolerated, producing the corresponding multisubstituted dibenzopentalenes with the different substituents on the aromatic rings in good to high yields under the optimized reaction conditions. The reaction proceeds through a Pd-catalyzed cascade carbopalladation and C-H activation. The use of the combined DBU and CsOPiv bases is crucial for the successful implementation of the present cross-annulation.