Intramolecular Palladium-Catalyzed Alkane C−H Arylation from Aryl Chlorides
作者:Sophie Rousseaux、Michaël Davi、Julien Sofack-Kreutzer、Cathleen Pierre、Christos E. Kefalidis、Eric Clot、Keith Fagnou、Olivier Baudoin
DOI:10.1021/ja1048847
日期:2010.8.11
efficient and general palladium-catalyzed intramolecular C(sp(3))-H arylation of (hetero)aryl chlorides, giving rise to a variety of valuable cyclobutarenes, indanes, indolines, dihydrobenzofurans, and indanones, are described. The use of aryl and heteroaryl chlorides significantly improves the scope of C(sp(3))-H arylation by facilitating the preparation of reaction substrates. Careful optimization studies
Synthesis of Cyclobutarenes by Palladium-Catalyzed C(sp3)-H Bond Arylation: Preparation of Methyl 7-Methylbicyclo[4.2.0]Octa-1,3,5-Triene-7-Carboxylate
by other methods. The reaction was found limited to substrates bearing a quaternary benzylic carbon, but benzocyclobutenes bearing a tertiarybenzylic carbon could be obtained indirectly from diesters by decarboxylation. Reaction substrates bearing a small substituent para to bromine gave an unexpected regioisomer that likely arose from a 1,4-palladium migration process. The formation of this "abnormal"