In the last few years, the development of versatile methodologies to incorporate trifluoromethyl groups into organic molecules has attracted significant attention in synthetic chemistry. This review ...gives an overview over the development on the trifluoromethylation of alkynes, which have not been solely discussed before. Formation of diverse C(sp, sp2, sp3)CF3 bonds are all covered in this review.
Versatile methodologies for the incorporation of trifluoromethyl groups into organic molecules have attracted significant attention in synthetic chemistry. This Minireview highlights the recent efforts on the development of trifluoromethylation of alkynes to construct various diverse C(sp, sp2, sp3)CF3 bonds by radical processes, or through transition‐metal catalysis by using nucleophilic or electrophilic trifluoromethylation reagents (see scheme).
We report here a new method for the synthesis of organohydrosilanes from phenols and ketones. This method is established through reductive C−Si coupling of chlorohydrosilanes via unconventional Si−Cl ...cleavage. The reaction offers access to aryl‐ and alkenylhydrosilanes with a scope that is complementary to those of the established methods. Electron‐rich, electron‐poor, and ortho‐/meta‐/para‐substituted (hetero)aryl electrophiles, as well as cyclic and acyclic alkenyl electrophiles, were coupled successfully. Functionalities, including Grignard‐sensitive groups (e.g., primary amine, amide, phenol, ketone, ester, and free indole), acid‐sensitive groups (e.g., ketal and THP protection), alkyl‐Cl, pyridine, furan, thiophene, Ar‐Bpin, and Ar‐SiMe3, were tolerated. Gram‐scale reaction, incorporation of ‐Si(H)R2 into complex biologically active molecules, and derivatization of formed organohydrosilanes are demonstrated.
A new C−Si bond‐forming reaction between R−X and Cl−Si(H)R2 was achieved using reductive nickel catalysis. This method offers access to structurally diverse aryl‐ and alkenylhydrosilanes from phenol and ketone derivatives. The reaction can be conducted on gram scale and allows for incorporating a hydrosilane moiety into biologically active molecules.
Recently, we reported that some dairy cows could produce high amounts of milk with high amounts of protein (defined as milk protein yield MPY) when a population was raised under the same nutritional ...and management condition, a potential new trait that can be used to increase high-quality milk production. It is unknown to what extent the rumen microbiome and its metabolites, as well as the host metabolism, contribute to MPY. Here, analysis of rumen metagenomics and metabolomics, together with serum metabolomics was performed to identify potential regulatory mechanisms of MPY at both the rumen microbiome and host levels.
Metagenomics analysis revealed that several Prevotella species were significantly more abundant in the rumen of high-MPY cows, contributing to improved functions related to branched-chain amino acid biosynthesis. In addition, the rumen microbiome of high-MPY cows had lower relative abundances of organisms with methanogen and methanogenesis functions, suggesting that these cows may produce less methane. Metabolomics analysis revealed that the relative concentrations of rumen microbial metabolites (mainly amino acids, carboxylic acids, and fatty acids) and the absolute concentrations of volatile fatty acids were higher in the high-MPY cows. By associating the rumen microbiome with the rumen metabolome, we found that specific microbial taxa (mainly Prevotella species) were positively correlated with ruminal microbial metabolites, including the amino acids and carbohydrates involved in glutathione, phenylalanine, starch, sucrose, and galactose metabolism. To detect the interactions between the rumen microbiome and host metabolism, we associated the rumen microbiome with the host serum metabolome and found that Prevotella species may affect the host's metabolism of amino acids (including glycine, serine, threonine, alanine, aspartate, glutamate, cysteine, and methionine). Further analysis using the linear mixed effect model estimated contributions to the variation in MPY based on different omics and revealed that the rumen microbial composition, functions, and metabolites, and the serum metabolites contributed 17.81, 21.56, 29.76, and 26.78%, respectively, to the host MPY.
These findings provide a fundamental understanding of how the microbiome-dependent and host-dependent mechanisms contribute to varied individualized performance in the milk production quality of dairy cows under the same management condition. This fundamental information is vital for the development of potential manipulation strategies to improve milk quality and production through precision feeding. Video Abstract.
Nonadiabatic holonomic quantum computation (NHQC) has been developed to shorten the construction times of geometric quantum gates. However, previous NHQC gates require the driving Hamiltonian to ...satisfy a set of rather restrictive conditions, reducing the robustness of the resulting geometric gates against control errors. Here we show that nonadiabatic geometric gates can be constructed in an extensible way, called NHQC+, for maintaining both flexibility and robustness against certain types of noises. Consequently, this approach makes it possible to incorporate most of the existing optimal control methods, such as dynamical decoupling, composite pulses, and a shortcut to adiabaticity, into the construction of single-looped geometric gates. Furthermore, this extensible approach of geometric quantum computation can be applied to various physical platforms such as superconducting qubits and nitrogen-vacancy centers. Specifically, we performed numerical simulation to show how the noise robustness in recent experimental implementations Phys. Rev. Lett. 119, 140503 (2017); Nat. Photonics 11, 309 (2017) can be significantly improved by our NHQC+.approach. These results cover a large class of new techniques combing the noise robustness of both geometric phase and optimal control theory.
Calcium is a universal secondary messenger that triggers many cellular responses. However, it is unclear how a calcium signal is coordinately decoded by different calcium sensors, which in turn ...regulate downstream targets to fulfill a specific physiological function. Here we show that SOS2-LIKE PROTEIN KINASE5 (PKS5) can negatively regulate the Salt-Overly-Sensitive signaling pathway in Arabidopsis. PKS5 can interact with and phosphorylate SOS2 at Ser
, promote the interaction between SOS2 and 14-3-3 proteins, and repress SOS2 activity. However, salt stress promotes an interaction between 14-3-3 proteins and PKS5, repressing its kinase activity and releasing inhibition of SOS2. We provide evidence that 14-3-3 proteins bind to Ca
, and that Ca
modulates 14-3-3-dependent regulation of SOS2 and PKS5 kinase activity. Our results suggest that a salt-induced calcium signal is decoded by 14-3-3 and SOS3/SCaBP8 proteins, which selectively activate/inactivate the downstream protein kinases SOS2 and PKS5 to regulate Na
homeostasis by coordinately mediating plasma membrane Na
/H
antiporter and H
-ATPase activity.
Molecular ferroelectrics are highly desirable for their easy and environmentally friendly processing, light weight, and mechanical flexibility. We found that diisopropylammonium bromide (DIPAB), a ...molecular crystal processed from aqueous solution, is a ferroelectric with a spontaneous polarization of 23 microcoulombs per square centimeter close to that of barium titanate (BTO), high Curie temperature of 426 kelvin (above that of BTO), large dielectric constant, and low dielectric loss. DIPAB exhibits good piezoelectric response and well-defined ferroelectric domains. These attributes make it a molecular alternative to perovskite ferroelectrics and ferroelectric polymers in sensing, actuation, data storage, electro-optics, and molecular or flexible electronics.
The cross‐electrophile coupling has become a powerful tool for C−C bond formation, but its potential for forging the C−Si bond remains unexplored. Here we report a cross‐electrophile Csp2‐Si coupling ...reaction of vinyl/aryl electrophiles with vinyl chlorosilanes. This new protocol offers an approach for facile and precise synthesis of organosilanes with high molecular diversity and complexity from readily available materials. The reaction proceeds under mild and non‐basic conditions, demonstrating a high step economy, broad substrate scope, wide functionality tolerance, and easy scalability. The synthetic utility of the method is shown by its efficient accessing of silicon bioisosteres, the design of new BCB‐monomers, and studies on the Hiyama cross‐coupling of vinylsilane products.
Organosilanes: A new C−Si bond‐forming reaction via C−X and Si−Cl cleavage was achieved by reductive nickel catalysis. This method bridges the gap between the cross‐electrophile coupling and organosilicon chemistry. It offers very mild reaction conditions for facile and precise synthesis of structurally versatile vinylsilanes that have found applications in many fields.
In the present study, catalytic fast co-pyrolysis of biomass and polyethylene (PE) was studied in a tandem micro-pyrolyzer using HZSM-5 as the catalyst. Cellulose, xylan and milled wood lignin were ...co-pyrolyzed with PE in both the presence and absence of catalyst to investigate the interaction between biomass and PE during thermal depolymerization and the following catalytic upgrade of the pyrolysis vapor. Co-pyrolysis with PE was found to increase the yields of furans and double anhydrosugar from cellulose up to 45%. Co-pyrolysis of xylan and PE increased not only the yields of furans and double anhydrosugar, but also the yield of acetic acid by 45%. Depolymerization of lignin was strongly promoted by PE as the yields of various phenolic monomers increased up to 43%. It was also found that the amounts of pyrolysis char and carbon oxides produced from biomass compounds decrease when co-pyrolyzed with PE. The presence of cellulose, xylan or lignin, on the other hand, facilitated depolymerization of PE by increasing the yields of olefins and alkanes with shorter carbon chains. When the pyrolysis vapor was upgraded by HZSM-5 zeolite catalyst, synergy increased the yields of hydrocarbons and suppressed the formation of catalytic coke, compared to when biomass compounds and PE were independently converted. During catalytic co-pyrolysis of cellulose and PE, the increase of the aromatic hydrocarbon yield was accompanied by the decrease in the selectivity of ethylene and propylene and no significant increase of total aliphatic hydrocarbons (i.e., the sum of olefins and alkanes), suggesting Diels–Alder reaction as the dominant reaction. On the other hand, catalytic co-pyrolysis of PE with xylan or lignin increased both the yields of aromatic and aliphatic hydrocarbons. The yield of alkanes decreased most significantly in the mixture of lignin and PE, suggesting that phenolic compounds act as strong hydrogen acceptors when they are deoxygenated. In the present study, red oak and PE were also catalytically co-pyrolyzed and the effects of pyrolysis temperature and catalyst temperature on product distribution and the extent of synergy were investigated. Both higher pyrolysis temperature and catalyst temperature were able to reduce the formation of catalytic coke and increase the yield of aromatic hydrocarbons monotonically. However, the maximum yield of aliphatic hydrocarbons was obtained at the intermediate pyrolysis temperature or catalyst temperature. Synergy between biomass and PE was consistent, regardless of changing pyrolysis temperatures. In comparison, the synergy became less significant when catalytic temperature was increased.
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•Chiral AIE compounds are recently developed very rapidly.•Chiral AIEgens display excellent chiral recognition, ee analysis and CPL properties.•Review paper about preparation of ...chiral AIEgens and their applications is scarce.
Due to immense potential in using as chemo/biosensors and solid emitters, aggregation-induced emission (AIE) phenomenon is attracting huge interest in scientific community. After endowed with chirality, the resultant chiral AIE luminogens (AIEgen), just like a tiger with added wings, can display more and stronger promising functionalities. Moreover, many classic luminophores can be transformed into AIEgens from notorious aggregation-caused quenching (ACQ) compounds as soon as they are attached with chiral groups. Compared with other chiral fluorescent receptors and chiral emitter, chiral AIEgens have displayed unique and outstanding advantages. Firstly, chiral AIEgen can differentiate two enantiomers of chiral analyte by 1.68 × 104 fold difference and get a chiral magnification up to 2.5 × 103 times due to aggregation. In addition, two enantiomers of up to 18 chiral carboxylic acids can be recognized just by using only one chiral AIEgen receptor and enantiomeric excess (ee) of chiral analytes at uM level can be measured. Furthermore, accurate ee analysis was carried out for the first time from fluorescence wavelength change rather than intensity change of the chiral AIEgen receptor. Therefore, the chiral AIEgens show unprecedentedly high selectivity, high sensitivity, high applicability, and high accuracy. Secondly, in the area of organic circularly polarized luminescence (CPL) materials, the CPL dissymmetry factor (glum) of chiral AIEgen can get to 1.42 that is near to the theoretical value of 2, making a breakthrough progress while the |glum| of previous organic luminophores is generally between 10−5 and 10−2. Furthermore, the highly efficient circularly polarized organic light-emitting diodes (CPOLEDs) are constructed for the first time by chiral AIEgens. Thirdly, chiral AIEgens enable novel display technology under different lighting conditions to be possible. More importantly, due to AIE effect, AIEgens are very beneficial for disclosing the mechanism of chiral transfer and magnification between molecules, which is thought to be the key for evolution of homochirality in natural world and preparation of chiral materials with hierarchical structures. For the above reason, chiral AIEgens have been brought to extensive attention and a large number of research works about them are reported. To take an overall view on chiral AIEgens and facilitate the development of chiral AIEgens, it is necessary to make a full review on the chiral AIEgens. This review covers the following contents: (1) construction of chiral AIEgens including propeller-like chiral AIEgens, chiral AIEgens with optically pure groups, polymer chiral AIEgens and supramolecular chiral AIEgen system; (2) chiral recognition and ee determination of chiral carboxylic acids, chiral amines, α-amino acids, and chiral neutral molecules by chiral AIEgens; (3) performance of chiral AIEgens in circular dichroism (CD), CPL and CPOLEDs; (4) other versatile application researches related to chiral AIEgens.
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