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The Miyaura borylation has shown to work for: Alkyl halides, [ 2 ] aryl halides, [ 1 ] [ 3 ] [ 4 ] aryl halides using tetrahydroxydiboron , [ 5 ] aryl halides using bis-boronic acid, [ 6 ] aryl triflates , [ 7 ] aryl mesylates , [ 8 ] vinyl halides, [ 9 ] vinyl halides of α,β-unsaturated carbonyl compounds, [ 10 ] and vinyl triflates.
Aromatic C–H borylation was developed by John F. Hartwig and Ishiyama using the diboron reagent Bis(pinacolato)diboron catalyzed by 4,4’-di-tert-butylbipyridine (dtbpy) and [Ir(COD)(OMe)] 2. [15] With this catalyst system the borylation of aromatic C–H bonds occurs with regioselectivity that is controlled by steric effects of
The Suzuki reaction or Suzuki coupling is an organic reaction that uses a palladium complex catalyst to cross-couple a boronic acid to an organohalide. [1] [2] [3] It was first published in 1979 by Akira Suzuki, and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their contribution to the discovery and development of noble metal catalysis in organic ...
A third method is by palladium catalysed reaction of aryl halides and triflates with diboronyl esters in a coupling reaction known as the Miyaura borylation reaction. An alternative to esters in this method is the use of diboronic acid or tetrahydroxydiboron ([B(OH 2)] 2). [14] [15] [16]
The Sandmeyer reaction can also be used to convert aryl amines to phenols proceeding through the formation of an aryl diazonium salt. In the presence of copper catalyst, such as copper(I) oxide , and an excess of copper(II) nitrate , this reaction takes place readily at room temperature neutral water. [ 28 ]
The aromatic chlorides and bromides are not easily substituted by iodide, though they may occur when appropriately catalyzed. The so-called "aromatic Finkelstein reaction" is catalyzed by copper(I) iodide in combination with diamine ligands. [9] Nickel bromide and tri-n-butylphosphine have been found to be suitable catalysts as well. [10]
An organic group's migration propensity depends on its ability to stabilize negative charge: alkynyl > aryl ≈ alkenyl > primary alkyl > secondary alkyl > tertiary alkyl. [33] Bis(norbornyl)borane and 9-BBN are often hydroboration reagents for this reason — only the hydroborated olefin is likely to migrate upon nucleophilic activation.
Since aryl iodides are more reactive than aryl bromides in the Sonogashira coupling, [4] the iodine end of 1-bromo-4-iodobenzene can be selectively coupled to a terminal acetylene while leaving the bromine end unreacted, by running the reaction at room temperature.