1258237-92-1Relevant academic research and scientific papers
Non-Innocent Behavior of Substrate Backbone Esters in Metal-Catalyzed Carbocyclizations and Friedel-Crafts Reactions of Enynes and Arenynes
Michelet, Bastien,Thiery, Guillaume,Bour, Christophe,Gandon, Vincent
, p. 10925 - 10938 (2015)
On the basis of DFT computations and experimental results, we show that the presence of the ester group in the backbone of organic substrates can influence the mechanism of metal-catalyzed carbocyclization reactions. The non-innocent role of the ester fun
A gallium-catalyzed cycloisomerization/Friedel-Crafts tandem
Li, Hui-Jing,Guillot, Regis,Gandon, Vincent
supporting information; experimental part, p. 8435 - 8449 (2011/03/19)
Under noble (Au, Pt, Ru) and group 13 (Ga, In) metals catalysis, 1,6-arenynes rearrange to give 1,2-dihydronaphthalenes in a high yielding, regiocontrolled fashion. When the reaction is carried out in the presence of electron-rich arenes (anisole, phenol, indole derivatives), Friedel-Crafts addition may follow the cycloisomerization step. Only GaX3 salts proved able to catalyze these two C-C bond formation events. This specificity of gallium has been exploited for the synthesis of valuable polycyclic compounds that would be very difficult to prepare otherwise. For instance, tetrahydroisoquinolines and tetrahydrobenzoazepines have been obtained by selective 6-exo-dig or 7-endo-dig cyclization of N-tethered 1,6-arenynes. DFT calculations were carried out to shed light on the mechanism and provide a rationale for this regiodivergency. Computations also reveal the fundamental role of the tether in the stabilization of carbocationic species. Differential reactivities of other types of substrates in gallium- and gold-catalyzed cascades are also exposed, showing that the two approaches are complementary. In particular, bimolecular Friedel-Crafts additions are facilitated under gallium catalysis.
