22 research outputs found
Synthesis of Secondary Aromatic Amides via Pd-Catalyzed Aminocarbonylation of Aryl Halides Using Carbamoylsilane as an Amide Source
Using <i>N</i>-methoxymethyl-<i>N</i>-organylcarbamoylÂ(trimethyl)Âsilanes
as secondary amides source, the direct transformation of aryl halides
into the corresponding secondary aromatic amides via palladium-catalyzed
aminocarbonylation is described. The reactions tolerated a broad range
of functional groups on the aryl ring except big steric hindrance
of substituent. The types and the relative position of substituents
on the aryl ring impact the coupling efficiency
Polycyclic Azetidines and Pyrrolidines via Palladium-Catalyzed Intramolecular Amination of Unactivated C(sp3)âH Bonds
A novel strategy to construct complex
polycyclic nitrogen-containing
heterocycles from aliphatic amines via picolinamide-assisted palladium-catalyzed
CâH bond activation reaction was reported. The reaction exhibits
broad substrate scope for the synthesis of various azabicyclic scaffolds,
including azetidines and tropane-class alkaloids. Application of this
method to naturally occurring (â)-<i>cis</i>-myrtanylamine,
an unprecedented type of carbonâcarbon bond activation, in
which the electron-pair involved initiates an intramolecular âS<sub>N</sub>2-likeâ displacement of a cyclopalladium-fragment from
a tertiary center, is described
Polycyclic Azetidines and Pyrrolidines via Palladium-Catalyzed Intramolecular Amination of Unactivated C(sp3)âH Bonds
A novel strategy to construct complex
polycyclic nitrogen-containing
heterocycles from aliphatic amines via picolinamide-assisted palladium-catalyzed
CâH bond activation reaction was reported. The reaction exhibits
broad substrate scope for the synthesis of various azabicyclic scaffolds,
including azetidines and tropane-class alkaloids. Application of this
method to naturally occurring (â)-<i>cis</i>-myrtanylamine,
an unprecedented type of carbonâcarbon bond activation, in
which the electron-pair involved initiates an intramolecular âS<sub>N</sub>2-likeâ displacement of a cyclopalladium-fragment from
a tertiary center, is described
Additional file 1: of Estimated assessment of cumulative dietary exposure to organophosphorus residues from tea infusion in China
Table S1. BMD at 10% AChE inhibition in female rat brain of OPs found in tea samples from the China monitoring programs. Table S2. CED at 20% AChE inhibition in female rat brain of OPs found in tea samples from the China monitoring programs. Table S3. TRs of OP residues to tea infusion. Table S4. Water solubility and octanol-water partition coefficient of OPs. (DOCX 28ĂÂ kb
Palladium-Catalyzed Unactivated C(sp<sup>3</sup>)âH Bond Activation and Intramolecular Amination of Carboxamides: A New Approach to βâLactams
An
efficient method to synthesize the β-lactams with high
regioselectivity via Pd-catalyzed CÂ(sp<sup>3</sup>)âH bond
activation and intramolecular amination of simple and readily available
aminoquinoline carboxamides was demonstrated. C<sub>6</sub>F<sub>5</sub>I plays a significant role in the formation of the CâN bond
of the four-membered ring β-lactams. High yield along with wide
substrate scope and functional group tolerance makes this reaction
applicable to build natural-product-derived β-lactams. This
method has been applied to the efficient synthesis of the β-lactamase
inhibitor MK-8712
Novel Dispersive Micro-Solid-Phase Extraction Combined with Ultrahigh-Performance Liquid ChromatographyâHigh-Resolution Mass Spectrometry To Determine Morpholine Residues in Citrus and Apples
This paper presents a new analytical
method for the determination
of morpholine residues in citrus and apples using a novel dispersive
micro-solid-phase extraction (DMSPE), followed by ultrahigh-performance
liquid chromatographyâhigh-resolution mass spectrometry (UHPLCâHRMS).
Samples were extracted with 1% formic acid in acetonitrile/water (1:1,
v/v) and then cleaned up using the DMSPE procedure. Morpholine from
the extract was adsorbed to a polymer cation exchange sorbent and
eluted with ammonium hydroxide/acetonitrile (3:97, v/v) through a
1 mL syringe with a 0.22 Îźm nylon syringe filter. All of the
samples were analyzed by UHPLCâHRMS/MS on a Waters Acquity
BEH hydrophilic interaction chromatography column using 0.1% formic
acid and 4 mM ammonium formate in water/acetonitrile as the mobile
phase with gradient elution. The method showed good linearity (<i>R</i><sup>2</sup> > 0.999) in the range of 1â100 Îźg/L
for the analyte. The limit of detection and limit of quantitation
values of morpholine were 2 and 5 Îźg/kg, respectively. The average
recoveries of morpholine from the citrus and apple samples spiked
at three different concentrations (5, 20, and 100 Îźg/kg) were
in a range from 78.4 to 102.7%
Palladium-Catalyzed Unactivated C(sp<sup>3</sup>)âH Bond Activation and Intramolecular Amination of Carboxamides: A New Approach to βâLactams
An
efficient method to synthesize the β-lactams with high
regioselectivity via Pd-catalyzed CÂ(sp<sup>3</sup>)âH bond
activation and intramolecular amination of simple and readily available
aminoquinoline carboxamides was demonstrated. C<sub>6</sub>F<sub>5</sub>I plays a significant role in the formation of the CâN bond
of the four-membered ring β-lactams. High yield along with wide
substrate scope and functional group tolerance makes this reaction
applicable to build natural-product-derived β-lactams. This
method has been applied to the efficient synthesis of the β-lactamase
inhibitor MK-8712
Palladium-Catalyzed Unactivated C(sp<sup>3</sup>)âH Bond Activation and Intramolecular Amination of Carboxamides: A New Approach to βâLactams
An
efficient method to synthesize the β-lactams with high
regioselectivity via Pd-catalyzed CÂ(sp<sup>3</sup>)âH bond
activation and intramolecular amination of simple and readily available
aminoquinoline carboxamides was demonstrated. C<sub>6</sub>F<sub>5</sub>I plays a significant role in the formation of the CâN bond
of the four-membered ring β-lactams. High yield along with wide
substrate scope and functional group tolerance makes this reaction
applicable to build natural-product-derived β-lactams. This
method has been applied to the efficient synthesis of the β-lactamase
inhibitor MK-8712
Palladium-Catalyzed Unactivated C(sp<sup>3</sup>)âH Bond Activation and Intramolecular Amination of Carboxamides: A New Approach to βâLactams
An
efficient method to synthesize the β-lactams with high
regioselectivity via Pd-catalyzed CÂ(sp<sup>3</sup>)âH bond
activation and intramolecular amination of simple and readily available
aminoquinoline carboxamides was demonstrated. C<sub>6</sub>F<sub>5</sub>I plays a significant role in the formation of the CâN bond
of the four-membered ring β-lactams. High yield along with wide
substrate scope and functional group tolerance makes this reaction
applicable to build natural-product-derived β-lactams. This
method has been applied to the efficient synthesis of the β-lactamase
inhibitor MK-8712
Stereoselective Synthesis of Diazabicyclic βâLactams through Intramolecular Amination of Unactivated C(sp<sup>3</sup>)âH Bonds of Carboxamides by Palladium Catalysis
An efficient CÂ(sp<sup>3</sup>)âH bond activation and intramolecular
amination reaction via palladium catalysis at the β-position
of carboxyamides to make β-lactams was described. The investigation
of the substrate scope showed that the current reaction conditions
favored activation of the β-methylene group. Short sequences
were developed for preparation of various diazabicyclic β-lactam
compounds with this method as the key step from chiral proline and
piperidine derivatives