278179-99-0Relevant academic research and scientific papers
Radical Truce-Smiles reactions on an isoxazole template: Scope and limitations
Rashid, Srood O.,Almadhhi, Sultan S.,Berrisford, David J.,Raftery, James,Vitorica-Yrezabal, Inigo,Whitehead, George,Quayle, Peter
, p. 2413 - 2430 (2019)
The use of TiCl3-HCl as promotor in the radical Truce-Smiles reactions of 2-(((3,5-dimethylisoxazol-4-yl)sulfonyl)oxy)benzenediazonium salts has been investigated in detail. During these reactions the desired Truce-Smiles rearrangement (via an ipso-substitution reaction) is accompanied by the formation of a number of by-products including dihydrobenzo[5,6][1,2]oxathiino[3,4-d]isoxazole 4,4-dioxides, dioxidobenzo[e][1,2]oxathiin-3-yl)ethan-1-ones, anilines and chloroaromatics. Replacing TiCl3-HCl by Cu(NO3)2-Cu2O as reductant in these reactions was found to afford broadly comparable product distributions. Competition and radical clock experiments also provide an indication of the relative susceptibility of the isoxazole nucleus towards attack by aryl radicals.
Observations on the enforced orthogonality concept for the synthesis of fully hindered biaryls by a tin-free intramolecular radical ipso substitution
Bonfand, Eric,Forslund, Linnea,Motherwell, William B.,Vázquez, Santiago
, p. 475 - 478 (2007/10/03)
Hindered biaryls have been simply prepared using diazonium salt precursors and an intramolecular free radical [1,5] ipso substitution protocol. The introduction of an additional substituent ortho to the diazonium group in the σ aryl radical donor further enforces the formation of ipso substitution products and hence fully hindered biaryls are the favoured products.
