Search results
Results from the WOW.Com Content Network
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]
[2] [3] Boronic acids, and boronic esters are common boryl groups incorporated into organic molecules through borylation reactions. [4] Boronic acids are trivalent boron-containing organic compounds that possess one alkyl substituent and two hydroxyl groups. Similarly, boronic esters possess one alkyl substituent and two ester groups.
Tris(pentafluorophenyl)borane, sometimes referred to as "BCF", is the chemical compound (C 6 F 5) 3 B.It is a white, volatile solid. The molecule consists of three pentafluorophenyl groups attached in a "paddle-wheel" manner to a central boron atom; the BC 3 core is planar.
Phenylboronic acid or benzeneboronic acid, abbreviated as PhB(OH) 2 where Ph is the phenyl group C 6 H 5 - and B(OH) 2 is a boronic acid containing a phenyl substituent and two hydroxyl groups attached to boron. Phenylboronic acid is a white powder and is commonly used in organic synthesis.
The first leg of the reaction sequence starts from the azeotropic dehydration of a boronic acid (1) such as one based on toluene to a boroxine (2). This boroxine reacts with the proline derivative ( 3d ) to form the basic oxazaborolidine CBS catalyst ( 4 ).
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. [7] [8]
The reaction is much slower with ketones than aldehydes. [40] For example, in Nicolaou's epothilones synthesis, asymmetric allylboration (with an allylborane derived from chiral alpha-pinene) is the first step in a two-carbon homologation to acetogenin: [41] Trifluoroborate salts are stabler than boronic acids and selectively alkylate aldehydes ...
The reaction of boron trichloride with alcohols was reported in 1931, and was used to prepare dimethoxyboron chloride, B(OCH 3) 2 Cl. [3] Egon Wiberg and Wilhelm Ruschmann used it to prepare tetrahydroxydiboron by first introducing the boron–boron bond by reduction with sodium and then hydrolysing the resulting tetramethoxydiboron, B 2 (OCH 3) 4, to produce what they termed sub-boric acid. [4]