154377-08-9Relevant academic research and scientific papers
Selective sulfenylative desulfonylation or decarbalkoxylation of α-sulfonyl malonates with DABCO or Bu3N: Reactivity and conformational analysis
Donnici, Claudio L.,Pereira, Elaine Henriques Teixeira,Lopes, Julio C. Dias,Marzorati, Liliana,Wladislaw, Blanka
scheme or table, p. 342 - 350 (2010/04/04)
The study on reactivity of severalαsubstituted αsulfonyl malonates toward 1,4-diazabicyclo[2.2.2]octane (DABCO) and Bu3N is described. The reactivity with DABCO revealed the possible competition between decarbalkoxylation and unexpected desulfonylation, depending on the-substituent, because of sterical hindrance around the electrophilic centers (SO2 and CO2R). The derivatives with crowded α-substituents suffer selective desulfonylation, and a novel and efficient desulfonylation method can be proposed. The dependence of the reactivity ofα-sulfonyl malonates on the sterical hindrance around the electrophilic centers is confirmed by conformational analysis (Macromodel/MM2* and Mopac/MP3). The carbanionic mechanism is proved because the corresponding protonated, deuterated, and sulfenylated products were obtained by addition of the corresponding electrophilic agents. Bu3N showed itself to be a novel selective decarbalkoxylation agent for any-substituted-sulfonyl malonate.
New Decarboxylation, De-ethoxycarbonylation and Desulfonylation, followed by Sulfenylation of some Half-Esters of Malonic Acids and α-Sulfonylmalonic Esters
Wladislaw, Blanka,Marzorati, Liliana,Donnici, Claudio L.
, p. 3167 - 3170 (2007/10/02)
The sulfenylation of some half-esters of malonic acids and some α-sulfonylmalonic esters with several sulfenylating reagents was investigated.Evidence was provided that in the case of the half-esters, in which NaH-dimethyl sulfoxide was employed, the formation of α,α-disulfenylated carboxylic esters may occur by two different reaction sequences, initiated either by dianion formation or decarboxylation.It is shown that, in the case of the α-sulfonylmalonic esters, in which diazabicyclooctane in refluxing toluene was employed, two competitive reactions may take place: de-ethoxycarbonylation or desulfonylation, both followed by sulfenylation.
