14 research outputs found
Synthesis of Biaryl Carboxylic Acids through a Cascade Suzuki–Miyaura Coupling/Friedel–Crafts Alkylation/Lewis-Acid-Catalyzed Rearrangement/Aromatization Process
In
this study, we present a series of 1,3-dicarbonyls that can
undergo a cascade Suzuki coupling, followed by a Friedel–Crafts
reaction to produce molecules containing polycyclic alcohols. These
polycyclic alcohols can then be converted into biaryl carboxylic acids
through ring-opening rearrangement reactions catalyzed by a Lewis
acid. The Friedel–Crafts reaction exhibits selective para-positioning
of the hydroxyl group and demonstrates good compatibility with functional
groups with a yield of up to 82%. Substrates with substituted hydroxyl
groups can also be converted into biaryl carboxylic acids through
a Lewis-acid-catalyzed ring-opening rearrangement
Direct Catalytic Asymmetric Reductive Amination of Simple Aromatic Ketones
A green method for chiral amine synthesis, the direct catalytic asymmetric reductive amination, was developed. Phenylhydrazide is an ideal nitrogen source for reductive amination. Molecular sieves play dual roles in this reaction. They help to remove H<sub>2</sub>O to form imine, as well as promote an imine reduction. f-Binaphane minimizes the inhibition effect from amines and helps the coordination of sterically demanding imines to the iridium center, thus leading to a smooth reaction
Iridium Catalysts with f‑Amphox Ligands: Asymmetric Hydrogenation of Simple Ketones
A series of modular and rich electronic
tridentate ferrocene aminophosphoxazoline
ligands (f-amphox) have been successfully developed and used in iridium-catalytic
asymmetric hydrogenation of simple ketones to afford corresponding
enantiomerically enriched alcohols under mild conditions with superb
activities and excellent enantioselectivities (up to 1 000 000
TON, almost all products up to >99% ee, full conversion). The resulting
chiral alcohols and their derivatives are important intermediates
in pharmaceuticals
Optimizing nitrogen application rate and plant density for improving cotton yield and nitrogen use efficiency in the North China Plain - Fig 1
<p>Leaf area index(LAI) of cotton at different growth periods in 2013(A) and 2014(B)Note: D1, D2, D3 indicate planting density at 3.00, 5.25, 7.50 plants m<sup>−2</sup> respectively, and N0, N1, N2, N3, N4 indicate nitrogen application rate at 0, 112.5, 225.0, 337.5 kg ha<sup>−1</sup> respectively. A, B indicate 2013 and 2014. Numbers at the same growth stage followed by the same small alphabet are not significantly different at the 5% level.</p
Seedcotton yield effect equation of PPD under different NAR treatments.
<p>Seedcotton yield effect equation of PPD under different NAR treatments.</p
Monthly weather summary during the cotton growing season in 2013 and 2014 at Anyang, Henan, China.
<p>Monthly weather summary during the cotton growing season in 2013 and 2014 at Anyang, Henan, China.</p
Effects of PPD and NAR on biological, economic (seedcotton and lint) yield and harvest index in 2013 and 2014.
<p>Effects of PPD and NAR on biological, economic (seedcotton and lint) yield and harvest index in 2013 and 2014.</p
iTRAQ-Based Quantitative Proteomic Analysis of Cotton Roots and Leaves Reveals Pathways Associated with Salt Stress
<div><p>Salinity is a major abiotic stress that affects plant growth and development. In this study, we performed a proteomic analysis of cotton roots and leaf tissue following exposure to saline stress. 611 and 1477 proteins were differentially expressed in the roots and leaves, respectively. In the roots, 259 (42%) proteins were up-regulated and 352 (58%) were down-regulated. In the leaves, 748 (51%) proteins were up-regulated and 729 (49%) were down-regulated. On the basis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, we concluded that the phenylalanine metabolism and starch and sucrose metabolism were active for energy homeostasis to cope with salt stress in cotton roots. Moreover, photosynthesis, pyruvate metabolism, glycolysis / gluconeogenesis, carbon fixation in photosynthetic organisms and phenylalanine metabolism were inhabited to reduce energy consumption. Characterization of the signaling pathways will help elucidate the mechanism activated by cotton in response to salt stress.</p></div