Dinitrogen tetroxide supported on polyvinylpyrrolidone (PVP–N2O4): a new nitrosating and coupling agent for thiols and a selective oxidant for sulfides and disulfides

N2O4 Chemisorbed onto n‐Propylsilica Kryptofix 21 and Kriptofix 22 as Two New Functional Polymers for the Fast Oxidation of Urazoles and 1,4‐Dihydropyridines

“…In continuation of our studies on the host‐guest chemistry of crown ethers , the synthesis and application of supported N 2 O 4 compounds , the oxidation of urazoles and 1,4‐dihydropyridines , and application of PVP‐H 2 O 2 for the epoxidation of α,β‐unsaturated ketones [15], we found that 3‐chloropropylsilica ( 1 ) was reacted with kriptofix 21 or 22 in the presence of triethylamine to form n ‐propylsilica kryptofix 21 ( III ) and kriptofix 22 ( IV ), respectively. The resulting composites were characterized by FT‐IR and XRD.…”

“…Apart from difficulties in handling the poisonous and corrosive dinitrogen tetroxide, the biggest disadvantage of using gaseous N 2 O 4 in organic reactions is its high reactivity, which usually causes undesired side reactions. To overcome the above mentioned limitations some reports are published on the use of N 2 O 4 complexes of organic , polymeric , and inorganic compounds as useful reagents in organic reactions. In 2001, we reported [NO + .Crown.H(NO 3 ) 2 − ] ( II ) as a crown ether‐supported N 2 O 4 for some organic transformations .…”

Fast and efficient green synthesis of thiosulfonate S-esters by microwave-supported permanganate oxidation of symmetrical disulfides

“…[1] "Symmetrical" thiosulfonates have been prepared by oxidation of the corresponding symmetrical disulfides by means of hydrogen peroxide, [4][5][6][7] m-chloroperbenzoic acid (MCPBA) and other peroxy acids, [7][8][9][10][11][12] dimethyldioxirane (DMD), [10] sulfoxides in the presence of a rhenium catalyst, [13] triphenylphosphite ozonide, [14] tetrabutylammonium peroxymonosulfate, [15] and dinitrogen tetroxide. [16,17] Symmetrical disulfides can also be converted into the corresponding thiosulfonates by chlorosolvolysis [18][19][20][21] and by means of Selectfluor TM (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)). [22,23] Since a symmetrical disulfide is the product formed primarily upon oxidation of a thiol, it has naturally been attempted with some success to synthesize "symmetrical" thiosulfonates directly from thiols, for example, by means of chlorosolvolysis [21] and by oxidation with dinitrogen tetraoxide [24][25][26] or hydrogen peroxide in the presence of titanium tetrachloride.…”

N2O4/SiO2 system as an efficient reagent for rapid and chemoselective conversion of trimethylsilyl ethers to the parent alcohols under nonaqueous conditions

“…Apart from difficulties in handling the poisonous and corrosive dinitrogen tetroxide, a serious disadvantage of utilizing gaseous N 2 O 4 in organic reactions, for example, its high reactivity which usually causes undesired side reactions. In order to overcome the above mentioned limitations, some reports have been published on the use of N 2 O 4 complexes of organic [2], polymeric [3] and inorganic compounds [4] as useful reagents in organic reactions.…”