56 research outputs found
Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones
A pyridine-directed,
rhodium-catalyzed C6-selective C–H
borylation of 2-pyridones with bisÂ(pinacolato)Âdiboron (pinB–Bpin)
has been developed. The reaction proceeds smoothly under relatively
mild conditions, and the corresponding C6-borylated 2-pyridones are
obtained with perfect site selectivity. Subsequent palladium-catalyzed
Suzuki–Miyaura cross-coupling is followed by the removal of
the pyridine directing group to form the C6-arylated NH-pyridone in
an acceptable overall yield
Asymmetric Synthesis of α‑Aminoboronic Acid Derivatives by Copper-Catalyzed Enantioselective Hydroamination
A copper-catalyzed
regio- and enantioÂselective hydroamination
of alkenyl dan boronates (dan =1,8-diaminonaphthyl) with hydrosilanes
and hydroxylamines proceeds to deliver the chiral α-aminoboronic
acids in good yields with high enantiomeric ratios. The key to success
is the introduction of an umpolung, electrophilic amination strategy.
The copper catalysis can provide an unprecedented catalytic asymmetric
approach to alkyl-substituted chiral α-aminoboronic acid derivatives
of great potential in the fields of organic synthesis and medicinal
chemistry
Copper-Mediated Oxidative Coupling of Benzamides with Maleimides via Directed C–H Cleavage
A CuÂ(OAc)<sub>2</sub>/Cy<sub>2</sub>NMe-mediated oxidative direct coupling of benzamides
with maleimides has been developed. The aromatic C–H alkenylation
with the aid of an 8-aminoquinoline-based bidentate directing group
is followed by an intramolecular aza-Michael-type addition to form
the isoindolone-incorporated spirosuccinimides, which are of potent
interest in medicinal chemistry
Copper/Bisphosphine Catalysts in the Internally Borylative Aminoboration of Unactivated Terminal Alkenes with Bis(pinacolato)diboron
CuÂ(I)/modified
dppbz catalyst systems for the regioselective aminoboration
of unactivated terminal alkenes have been developed. The bisphosphine-based
Cu catalysis enables the introduction of the readily transformable
Bpin group at the more congested internal position and shows better
regioselectivity for broader terminal alkenes involving sterically
demanding allylbenzenes, which are relatively challenging substrates
in the previous IPrCuBr catalysis. Additionally, the second-generation
catalyst systems accommodate the <i>exo</i>-methylene-type
disubstituted alkenes to deliver the corresponding aminoborated products
in good yields with a high regioselectivity
Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones
A pyridine-directed,
rhodium-catalyzed C6-selective C–H
borylation of 2-pyridones with bisÂ(pinacolato)Âdiboron (pinB–Bpin)
has been developed. The reaction proceeds smoothly under relatively
mild conditions, and the corresponding C6-borylated 2-pyridones are
obtained with perfect site selectivity. Subsequent palladium-catalyzed
Suzuki–Miyaura cross-coupling is followed by the removal of
the pyridine directing group to form the C6-arylated NH-pyridone in
an acceptable overall yield
Copper-Mediated Oxidative Coupling of Benzamides with Maleimides via Directed C–H Cleavage
A CuÂ(OAc)<sub>2</sub>/Cy<sub>2</sub>NMe-mediated oxidative direct coupling of benzamides
with maleimides has been developed. The aromatic C–H alkenylation
with the aid of an 8-aminoquinoline-based bidentate directing group
is followed by an intramolecular aza-Michael-type addition to form
the isoindolone-incorporated spirosuccinimides, which are of potent
interest in medicinal chemistry
Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones
A pyridine-directed,
rhodium-catalyzed C6-selective C–H
borylation of 2-pyridones with bisÂ(pinacolato)Âdiboron (pinB–Bpin)
has been developed. The reaction proceeds smoothly under relatively
mild conditions, and the corresponding C6-borylated 2-pyridones are
obtained with perfect site selectivity. Subsequent palladium-catalyzed
Suzuki–Miyaura cross-coupling is followed by the removal of
the pyridine directing group to form the C6-arylated NH-pyridone in
an acceptable overall yield
Rhodium-Catalyzed C6-Selective C–H Borylation of 2‑Pyridones
A pyridine-directed,
rhodium-catalyzed C6-selective C–H
borylation of 2-pyridones with bisÂ(pinacolato)Âdiboron (pinB–Bpin)
has been developed. The reaction proceeds smoothly under relatively
mild conditions, and the corresponding C6-borylated 2-pyridones are
obtained with perfect site selectivity. Subsequent palladium-catalyzed
Suzuki–Miyaura cross-coupling is followed by the removal of
the pyridine directing group to form the C6-arylated NH-pyridone in
an acceptable overall yield
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