Search results
Results from the WOW.Com Content Network
Meta-selective borylation: Meta-selective C–H borylation is an important synthetic transformation, which was discovered in 2002 by Smith III from Michigan State University, USA. However, this meta borylation was completely sterically directed and was limited to only 1,3-disubstituted benzenes.
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.
Borylation of S-H bonds in thiols by a dehydrogenative process has also been observed. Alcohols and amines such as tert-Butanol and tert-Butylamine form stable products that prevent catalysis due to a strong π-bond between the N/O atom's lone pair and boron, whereas the same is not true for thiols, thus allowing for successful catalysis.
Transforming C-H bonds into C-B bonds through borylation has been thoroughly investigated due to their utility in synthesis (i.e. for cross-coupling reactions). John F. Hartwig reported a highly regioselective arene and alkane borylation catalyzed by a rhodium complex. In the case of alkanes, exclusive terminal functionalization was observed.
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]
A heterobimetallic bond-breaking process is also employed in the IPrCuFp-catalyzed C-H borylation system developed by Mankad (Scheme 5). [15] Bimetallic cleavage of the B-H bond in pinacolborane generates a copper hydride (IPrCu-H) and an iron boryl [(pin)B-Fp], the latter of which borylates unactivated arenes upon UV irradiation.
Structure of the platinacyclobutane PtC 3 H 6 (bipy) derived from activation of cyclopropane.. In organometallic chemistry, the activation of cyclopropanes by transition metals is a research theme with implications for organic synthesis and homogeneous catalysis. [1]
Organoboron. Organoboron chemistry or organoborane chemistry studies organoboron compounds, also called organoboranes.These chemical compounds combine boron and carbon; typically, they are organic derivatives of borane (BH 3), as in the trialkyl boranes.