Chemical process intended to reverse the polarity of a molecular functional group
In organic chemistry, umpolung (German:[ˈʔʊmˌpoːlʊŋ]) or polarity inversion is the chemical modification of a functional group with the aim of the reversal of polarity of that group.[1][2] This modification allows secondary reactions of this functional group that would otherwise not be possible.[3] The concept was introduced by D. Seebach (hence the German word umpolung for reversed polarity) and E.J. Corey. Polarity analysis during retrosynthetic analysis tells a chemist when umpolung tactics are required to synthesize a target molecule.
^Seebach, D. (1979). "Methods of Reactivity Umpolung". Angewandte Chemie International Edition in English. 18 (4): 239–258. doi:10.1002/anie.197902393.
^Gröbel, B. T.; Seebach, D. (1977). "Umpolung of the Reactivity of Carbonyl Compounds Through Sulfur-Containing Reagents". Synthesis. 1977 (6): 357. doi:10.1055/s-1977-24412. S2CID95705677.
^Seebach, D.; Corey, E. J. (1975). "Generation and synthetic applications of 2-lithio-1,3-dithianes". The Journal of Organic Chemistry. 40 (2): 231. doi:10.1021/jo00890a018.