[MoO3(2,2′–bipy)]n catalyzed oxidation of amines and sulfides
作者:Irene Tosi、Carolina Vurchio、Marta Abrantes、Isabel S. Gonçalves、Martyn Pillinger、Fabrizio Cavani、Franca M. Cordero、Alberto Brandi
DOI:10.1016/j.catcom.2017.09.022
日期:2018.1
catalyst [MoO3(2,2′–bipy)]n has been employed in the oxidation of secondary amines to nitrones, and sulfides to sulfoxides or sulfones, using tert–butylhydroperoxide (TBHP) as the stoichiometric oxidant. Whereas the oxidation of amines occurs with less proficiency with respect to other previously studied polymeric Mo catalysts, the oxidation of sulfides occurs in high yield and selectivity. The catalyst
Studies on the oxidation of 1, 3-dithiane and 5, 5-disubstituted analogues including X-ray crystal structure, equilibration studies and pK a measurements on selected oxides
作者:Varinder K. Aggarwal、Ian W. Davies、Richard Franklin、John Maddock、Mary F. Mahon、Kieran C. Molloy
DOI:10.1039/p19940002363
日期:——
Oxidation of 1,3-dithiane has been carried out using eight different oxidants under several different reaction conditions. The most favourable conditions for obtaining the required trans-1,3-dithiane 1,3-dioxide were to use either MCPBA in Et(2)O or NaIO4 in MeOH-H2O. Other 5,5-disubstituted-1,3-dithianes were also prepared and subjected to similar oxidations. For these compounds the best oxidant for obtaining the trans-dioxides was O-3. A rationalisation for the stereochemical outcome of the oxidations is presented and requires that trans-1,3-dithiane 1,3-dioxide is more stable than cis-1,3-dithiane 1,3-dioxide. This is borne out by equilibration studies of the two diastereoisomeric sulfoxides using N2O4. A rationalisation for the greater stability of the trans compared to the cis isomer is also presented and fits with the pK(a) values and melting points of the two compounds.