Regioselective Borylation of the C–H Bonds in Alkylamines and Alkyl Ethers. Observation and Origin of High Reactivity of Primary C–H Bonds Beta to Nitrogen and Oxygen
作者:Qian Li、Carl W. Liskey、John F. Hartwig
DOI:10.1021/ja503676d
日期:2014.6.18
Borylation of aliphatic C-H bonds in alkylamines and alkyl ethers to form primary aminoalkyl and alkoxyalkyl boronate esters and studies on the origin of the regioselectivity of these reactions are reported. The products of these reactions can be used directly in Suzuki-Miyaura cross-coupling reactions or isolated as air-stable potassium trifluoroborate salts. Selective borylation of the terminal C-H
Iridium-catalysed borylation of sterically hindered C(sp<sup>3</sup>)–H bonds: remarkable rate acceleration by a catalytic amount of potassium tert-butoxide
The C(sp(3))-H bonds located on the methyl groups of an isopropyl group participate in iridium-catalysed C-H borylation with bis(pinacolato)diboron via a significant rate acceleration caused by a catalytic amount of t-BuOK.
Regiospecific Functionalization of Methyl C−H Bonds of Alkyl Groups in Reagents with Heteroatom Functionality
作者:Joshua D. Lawrence、Makoto Takahashi、Chulsung Bae、John F. Hartwig
DOI:10.1021/ja044933x
日期:2004.12.1
rhodium-catalyzed borylation of saturated terminal C-H bonds in molecules with existing functionality. Moderate to good yields were obtained with the organic substrate in excess and as limiting reagent. The borylations of trialkylamines, protected alcohols, protected ketones, and fluoroalkanes occurred regiospecifically at the methyl group that is least sterically hindered. Reactions were also conducted that probed
Approaching a Holy Grail? A regioselective functionalization of alkanes occurs with commercially available rhenium catalysts and borane reagents under photochemical conditions [Eq. (1)]. Mechanistic studies indicate that the regioselectivity results from a direct thermal reaction of a photochemically generated 16-electron boryl complex with alkane.
Iridium‐Catalyzed C(sp
<sup>3</sup>
)−H Borylation Using Silyl‐Bipyridine Pincer Ligands
作者:Ryohei Kawazu、Takeru Torigoe、Yoichiro Kuninobu
DOI:10.1002/anie.202202327
日期:2022.5.23
NNSi pincer ligands served as suitable ligands for iridium-catalyzed C(sp3)−H borylation. Among them, a phenanthroline-based ligand was shown to be an excellent one. The formation of an iridiumcomplex bearing a quinoline-based NNSi pincer ligand from [IrCl(cod)]2 was observed, and the catalytic activity of the complex was demonstrated.