[bharathi]

hi all,
Could someone help me to know if dimethyl sulfoxide is a decarboxylating agent.
One of the reactions I worked on involves ester hydrolysis followed by elimination of CO2 in NaOH+water+dimethylsulfoxide. However , this reaction is not proceeding in the absence of dimethylsulfoxide. What role has dimethylsulfoxide got to do in elimating Co2

Regards,
Bharathi

[Arsenic]

Synthetic applications and mechanism studies of the decarbalkoxylations of geminal diesters and related systems effected in dimethyl sulfoxide by water and/or by water with added salts
J. Org. Chem.; 1978; 43(1); 138-147

Conclusions
Certain activated esters have been shown to undergo rapid
decarbalkoxylations in wet Me2SO while other substrates
require the presence of salts. The data indicate that LiCl-
HZO-MezSO is an excellent salt for preparative decarbalkoxylations.
The decarbalkoxylation mechanism is a blend
of BALa~nd B ~ cp2a thways which are dependent on substrate
structure and nucleophile type. A variety of salts can be effectively
used in this process.

I really don't know if the above is relevant or not

[movies]

The reaction with LiCl in DMSO is a special case called the Krapcho decarboxylation.  In that case the DMSO is necessary to make the chloride ion act as a stronger nucleophile.

In the absence of LiCl, then the DMSO may just be there to help solubilize the organic molecule in the aqueous base.