Dimethylsulfoxide trans effect

DMSO, dimethylsulfoxide DMA, dimethylacetamide DMF, dimethyl-formamide). It seems difficult to obtain any single and simple order of cis and trans effects out of the above results there are probably seyeral effects in operation. 

Chemical modification of polymer-bound active ester groups is also subject to strong solvent effects. In copolyfAOTcp-styrere), both aminolysis and transesterification with primary alcohols are positively influenced by solvents in the order of dimethylformamide (DMF) > dioxan > diloroform > chlorobenzene > dimethylsulfoxide (DMSO). However, trans-esterification with phenols proceeds in dioxan, but not in DMF. The last-nan d solvent effect is probably related to inactivation of the phenolate ion in DMF, as observed ako for the acylation of polymer-bound phenolic groups by soluble trichlorophenyl esters [64]. 

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