Toward ideal (Trans) esterification by use of fluorous distannoxane catalysts

1,3-Disubstituted tetrakis(fluoroalkyl)distannoxanes, (XR(2)SnOSnR(2)y)(2) (R = C6H3C2H4 and C4F9C2H4), are highly fluorophilic and exhibit large partition coefficients in favor of fluorocarbon solvents over common organic solvents due to a double-layered structure where the stannoxane core is covered by fluoroalkyl groups. Under catalysis of these Lewis acids, fluorous technology allows novel transesterification and esterification in which a 100% yield of the desired esters is achievable with reactants in a strict 1:1 ratio. The catalysts are recovered from the fluorous phase quantitatively. More practically, the catalyst in fluorocarbon solution can be recycled for use in the next reaction repeatedly.