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In organic chemistry, the Arndt–Eistert reaction is the conversion of a carboxylic acid to its homologue. It is named for the German chemists Fritz Arndt (1885–1969) and Bernd Eistert (1902–1978). The method entails treating an acid chlorides with diazomethane. It is a popular method of producing β-amino acids from α-amino acids. [1]
The Negishi coupling was implemented in the synthesis of δ-trans-tocotrienoloic acid by Hecht and Maloney coupling the sp 3 homopropargyl zinc reagent 8 with sp 2 vinyl iodide 9. [43] The reaction proceeded with quantitative yield, coupling fragments mid-synthesis en route to the stereoselectively synthesized natural product δ-trans ...
An overarching aspect of mechanistic transition metal chemistry is the kinetic lability of the complex illustrated by the exchange of free and bound water in the prototypical complexes [M(H 2 O) 6] n+: [M(H 2 O) 6] n+ + 6 H 2 O* → [M(H 2 O*) 6] n+ + 6 H 2 O where H 2 O* denotes isotopically enriched water, e.g., H 2 17 O
An acid which has more of a tendency to donate a hydrogen ion than the limiting acid will be a strong acid in the solvent considered, and will exist mostly or entirely in its dissociated form. Likewise, the limiting base in a given solvent is the solvate ion, such as OH − ion, in water. A base which has more affinity for protons than the ...
For example, a consistent system for benzylic aryl imines uses the P,N ligand SIPHOX in conjunction with iridium(I) in a cationic complex to achieve asymmetric hydrogenation with ee >90%. [52] An efficient catalyst for ketones, (turnover number (TON) up to 4,550,000 and ee up to 99.9%) is an iridium(I) system with a closely related tridentate ...
In the table above, it can be seen that water is the most polar-solvent, followed by DMSO, and then acetonitrile. Consider the following acid dissociation equilibrium: HA ⇌ A − + H + Water, being the most polar-solvent listed above, stabilizes the ionized species to a greater extent than does DMSO or Acetonitrile.
The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester RCO 2 H + R′OH ⇌ RCO 2 R′ + H 2 O. Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water.
A well-known electrosynthesis is the Kolbe electrolysis, in which two carboxylic acids decarboxylate, and the remaining structures bond together:; A variation is called the non-Kolbe reaction when a heteroatom (nitrogen or oxygen) is present at the α-position.