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Phenylboronic acid participates in numerous cross coupling reactions where it serves as a source of a phenyl group. One example is the Suzuki reaction where, in the presence of a Pd(0) catalyst and base, phenylboronic acid and vinyl halides are coupled to produce phenyl alkenes . [ 7 ]
Protodeboronation is a well-known undesired side reaction, and frequently associated with metal-catalysed coupling reactions that utilise boronic acids (see Suzuki reaction). [1] For a given boronic acid, the propensity to undergo protodeboronation is highly variable and dependent on various factors, such as the reaction conditions employed and ...
4-Formylphenyl boronic acid crystallizes in colorless needles [2] or is obtained as an odorless, whitish powder, which dissolves little in cold but better in hot water. The compound is quite stable [4] and readily forms dimers and cyclic trimeric anhydrides, which complicate purification and tend to protodeboronize, a secondary reaction that occurs frequently in the Suzuki coupling, with ...
The general structure of a boronic acid, where R is a substituent.. A boronic acid is an organic compound related to boric acid (B(OH) 3) in which one of the three hydroxyl groups (−OH) is replaced by an alkyl or aryl group (represented by R in the general formula R−B(OH) 2). [1]
The reaction is carried out under harsh conditions (24-hr reflux in 1,4-dioxane), but the resultant carboxylic acid is obtained in reasonable yield. Usage of α-ketoacids instead of glyoxylic acid does not diminish yields. 1,3,5-trioxygenated benzene derivatives can also be used in lieu of tertiary aromatic amines. [15]
The mechanism of organotrifluoroborate-based Suzuki-Miyaura coupling reactions has recently been investigated in detail. The organotrifluoroborate hydrolyses to the corresponding boronic acid in situ , so a boronic acid can be used in place of an organotrifluoroborate, as long as it is added slowly and carefully.
Desulfonylation reactions are chemical reactions leading to the removal of a sulfonyl group from organic compounds. As the sulfonyl functional group is electron -withdrawing, [ 1 ] methods for cleaving the sulfur –carbon bonds of sulfones are typically reductive in nature.
Sulfanilic acid can be produced by sulfonation of aniline with concentrated sulfuric acid. [5] This proceeds via phenylsulfamic acid; a zwitterion with a N-S bond. Eugen Bamberger originally proposed a mechanism involving a series of intramolecular rearrangements, with phenylsulfamic acid forming orthanilic acid, which rearranged to sulfanilic acid on heating.