Arynes were found to insert into a carbonâtin bond of
alkynyl- and vinylstannanes in the presence of a catalytic amount of a
palladiumâiminophosphine complex to afford ortho-substituted
arylstannanes, which were convertible into a wide variety of
1,2-disubstituted arenes via carbonâcarbon bond forming
reactions.
Transition metal-free hydroarylation of unactivated alkynes was achieved by combining a Brønsted acid catalyst and a two-phase solvent system consisting of 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) and cyclohexane. This protocol is applicable to a wide variety of 2-alkynylbiaryls which leads to the synthesis of substituted phenanthrenes via 6-endo-selective ring closure. The biphasic system achieves
Synthesis of Polycyclic Aromatics and Heteroaromatics via Electrophilic Cyclization
作者:Tuanli Yao、Marino A. Campo、Richard C. Larock
DOI:10.1021/jo050104y
日期:2005.4.1
A variety of substituted polycyclic aromatics are readily prepared in good to excellent yields under very mild reaction conditions by the reaction of 2-(1-alkynyl)biphenyls with ICl, I-2, NBS, and p-O2NC6H4SCl. This methodology readily accommodates various functional groups and has been successfully extended to systems containing a variety of polycyclic and heterocyclic rings.