In organic chemistry, umpolung (German: [ˈʔʊmˌpoːlʊŋ]) or polarity inversion is the chemical modification of a functional group with the aim of the reversal...

The Corey–Seebach reaction, or Seebach Umpolung is a name reaction of organic chemistry that allows for acylation by converting aldehydes into lithiated...

Polarity inversion may refer to: Polarity inversion (chemistry) (aka Umpolung), in organic chemistry Polarity inversion (differential pairs), swapping...

forget about their language and their origin. As a neologism, it echoes Umpolung, 'polarity inversion', leading to an interpretation akin to "ethnicity...

Aldol addition Acyloin condensation Cannizzaro reaction Stetter reaction Umpolung Menon, Rajeev S.; Biju, Akkattu T.; Nair, Vijay (2016). "Recent advances...

Boluda CJ, Juncá C, Soto E, de la Cruz D, Peña A (13 December 2019). "Umpolung in reactions catalyzed by thiamine pyrophosphate dependent enzymes". Ciencia...

inversion of polarity between R'(H)Cδ+=Oδ− and R'CLi(SR)2 is referred to as umpolung. The reaction is commonly performed using the 1,3-dithiane. The lithiated...

chemistry since the 1980s. They are related to enolates, but represent an umpolung of their reactivity. Homoenolates can be formed with a variety of different...

chloride is used to remove dithiane groups attached to a carbonyl in an umpolung reaction. This reaction exploits the high affinity of Hg2+ for anionic...

triazolium salts to be effective. The Stetter reaction is an example of umpolung chemistry, as the inherent polarity of the aldehyde is reversed by the...

produce an acyl anion equivalent (see cyanohydrin or aldehyde-dithiane umpolung chemistry, as well as benzoin condensation). This anion attacks S1 of an...

formaldehyde. The reactivity of this dithiane illustrates the concept of umpolung. Alkylation gives thioethers, e.g. 1,5-dithiacyclooctane. The unpleasant...

apparatus Meitnerium Mischmetall (lit. "mixed metal"), alloy Roentgenium Umpolung (organic chemistry) Wolfram Zwitterion Allumwandlung Blitz chess, from...

They represent a subclass of sulfides. The thioacetals are useful in "umpolung" of carbonyl groups. Thioacetals and thioketals can also be used to protect...

reactivity in displacement and addition reactions. Dithianation introduced umpolung chemistry, now a key concept in organic synthesis. The formations of dithianes...

of Hg(II) for thiolates. 1,3-Dithianes are more importantly employed in umpolung reactions, such as the Corey–Seebach reaction: 1,4-Dithiane is an organosulfur...

resulting anion can be C-alkylated. The process is the foundation of the umpolung phenomenon. Like 1,2-ethanedithiol, propanedithiol forms complexes with...

Taylor, Carol M. (2006-08-01). "β-Glycosides of Hydroxyproline via an Umpolung Approach". Organic Letters. 8 (18): 3959–3962. doi:10.1021/ol061424m. ISSN 1523-7060...

chemistry and on the synthesis of beta-peptides. The development of the umpolung, a polarity inversion of the carbonyl group, with 1,3-propanedithiol together...

S.; Yatham V. R.; Neudörfl J.-M.; Schlörer N. E.; Teles J. H. (2012). "Umpolung by N-Heterocyclic Carbenes: Generation and Reactivity of the Elusive 2...

S2CID 11653420. Dai, Xijie; Li, Chenchen; Li, Chao-Jun (April 2021). "Carbonyl umpolung as organometallic reagent surrogates". Chemical Society Reviews. 50 (19):...

(NHCs) are an emerging class of organocatalysts that are able to induce Umpolung reactivity as well as normal polarity transformations, however until recently...

doi:10.1038/nchem.1607. Xavier Bugaut, Frank Glorius: Organocatalytic umpolung: N-heterocyclic carbenes and beyond. In: Chemical Society Reviews. 41,...

intermediates may also intercept nucleophiles in a process that involves umpolung at the α carbon. In addition, because reduction of monohalo ketones produces...

PMID 15543313. Streuff, Jan (2011). "A titanium(III)-catalyzed redox Umpolung reaction for the reductive cross-coupling of enones with acrylonitriles"...

W.; Shevchenko, Nikolay; Alabugin, Igor V. (2013). ""Stereoelectronic Umpolung": Converting a p-Donor into a σ-Acceptor via Electron Injection and a Conformational...

formation of the other allylic analog by logic similar to cyanide-type umpolung. It then later provides a good leaving group for formation of the iminium...