Gregory Rosocha, R. Batey
Oct 14, 2013
Citations
0
Influential Citations
19
Citations
Journal
Tetrahedron
Abstract
Abstract 2-Bromo-1-aryl substituted indenes can be synthesized from 1,2-diaryl substituted gem -dibromocyclopropanes via a domino reaction sequence. The cascade reaction involves silver(I) promoted ionization and 2π-disrotatory electrocyclic ring-opening, followed by a 4π-conrotatory electrocyclic ring closing reaction of the allylic carbocation intermediate. Reaction conditions utilize silver tetrafluoroborate (AgBF 4 ) in dichloroethane at 65 °C. Selectivity effects for the electrocyclization were also studied. The 2-bromoindenes can be further functionalized using cross-coupling reactions, such as the Suzuki–Miyaura protocol. The alkene π-bond of the indenes can also be isomerized to give the thermodynamically more stable 2-bromo-3-aryl-1 H -indene isomers using triethylamine in dichloromethane at room temperature.