Temperature-Controlled Divergent Synthesis of Pyrazoles and 1-Tosyl-1H-pyrazoles under Transition-Metal-Catalyst- and Oxidant-Free Conditions.

Herein, a general and practical temperature-controlled approach for the divergent synthesis of pyrazoles and 1-tosyl-1H-pyrazoles via electrophilic cyclization in the absence of transition-metal catalysts and oxidants was developed. The desired products were obtained in moderate to excellent yields from common starting materials in both ionic liquids and ethanol by simply tuning the reaction temperature. This strategy employs easily synthesized substrates, mild reaction conditions, and excellent functional-group tolerance.

Regioselective Cycloaddition of Alkenes with tert-butyl Nitrite: A Cascade Approach to the Formation of Δ2-Isoxazolines.

A route for cycloaddition reaction of alkenes and tert-butyl nitrite to synthesize Δ2-isoxazolines has been developed. The overall process involves the formation of multiple chemical bonds without the use of a catalyst. This methodology features mild reaction conditions and good functional group tolerance, providing a direct approach for the preparation of isoxazolines.

Electrochemical Phenyl-Carbonyl Coupling Reaction of Aromatic Aldehydes or Ketones.

An electrochemical phenyl-carbonyl coupling reaction of aromatic aldehydes or ketones to synthesize 4-(hydroxy(phenyl)methyl)benzaldehyde derivatives has been developed. The method shows high chemoselectivity, broad functional group compatibility, atom economy, and environmental benignity and has good potential applicability.

Synthesis of (E)-2-(1-(methoxyimino)ethyl)-2-phenylbenzofuran-3(2H)-ones from (E)-1-(benzofuran-2-yl)ethan-1-one O-methyl oximes and iodobenzenes via a palladium-catalyzed dearomative arylation/oxidation reaction.

A new method has been successfully developed that offers a facile and reliable approach for synthesizing (E)-2-(1-(methoxyimino)ethyl)-2-phenylbenzofuran-3(2H)-one, providing 28 compounds. This optimized process enables efficient preparation of a wide range of compounds using readily available (E)-1-(benzofuran-2-yl)ethan-1-one O-methyl oxime and iodobenzene, and provides alternative ideas for the structural modification of benzofuran ketones.

Genome-Wide Association Analysis of Fruit Shape-Related Traits in Areca catechu.

The areca palm (Areca catechu L.) is one of the most economically important palm trees in tropical areas. To inform areca breeding programs, it is critical to characterize the genetic bases of the mechanisms that regulate areca fruit shape and to identify candidate genes related to fruit-shape traits. However, few previous studies have mined candidate genes associated with areca fruit shape. Here, the fruits produced by 137 areca germplasms were divided into three categories (spherical, oval, and columnar) based on the fruit shape index. A total of 45,094 high-quality single-nucleotide polymorphisms (SNPs) were identified across the 137 areca cultivars. Phylogenetic analysis clustered the areca cultivars into four subgroups. A genome-wide association study that used a mixed linear model identified the 200 loci that were the most significantly associated with fruit-shape traits in the germplasms. In addition, 86 candidate genes associated with areca fruit-shape traits were further mined. Among the proteins encoded by these candidate genes were UDP-glucosyltransferase 85A2, the ABA-responsive element binding factor GBF4, E3 ubiquitin-protein ligase SIAH1, and LRR receptor-like serine/threonine-protein kinase ERECTA. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that the gene that encoded UDP-glycosyltransferase, UGT85A2, was significantly upregulated in columnar fruits as compared to spherical and oval fruits. The identification of molecular markers that are closely related to fruit-shape traits not only provides genetic data for areca breeding, but it also provides new insights into the shape formation mechanisms of drupes.

Catalyst-Free α-Alkylation-α-Hydroxylation of Oxindole with Alcohols.

3-Alkyl-3-hydroxyoxindoles, a subclass of oxindole products, have antioxidant, neuroprotective, anticancer, and anti-HIV activities. In this study, a green and economical protocol for the synthesis of 3-alkyl-3-hydroxyoxindoles is developed for the first time via α-alkylation-α-hydroxylation of oxindole with benzyl alcohols without using any transition-metal catalysts in yields of 29-93%.

Tandem Reduction, Ammonolysis, Condensation, and Deamination Reaction for Synthesis of Benzothiadiazines and 1-(Phenylsulfonyl)-1H-benzimidazoles.

A novel route for a SnCl2-promoted tandem reduction, ammonolysis, condensation, and deamination reaction which uses nitrile and 2-nitro-N-phenylbenzenesulfonamide/N-(2-nitrophenyl)benzenesulfonamide to synthesize derivatives of benzothiadiazine/1-(phenylsulfonyl)-1H-benzimidazole has been developed. The method features convenient operation and good functional group tolerance. In addition, it employs unsensitive and inexpensive SnCl2/i-PrOH as the reaction reagent and provides a direct approach for the synthesis of pharmaceutically important targets.

Anion Modified Spin Crossover in [Fe(qsal-4-F)]+ Complexes with a 4-Position Substituted Qsal Ligand.

Four iron(III) complexes, [Fe(qsal-4-F)2]Y·sol (Hqsal-4-F = 4-fluoro-N-(8-quinolyl)salicylaldimine; Y = NO3-, sol = 0.91MeOH·0.57H2O (1NO3); Y = PF6- (2PF6); Y = BF4- (3BF4); Y = OTf-, sol =1.5MeOH (4OTf)), with a new 4-position substituted qsal type ligand Hqsal-4-F have been synthesized and structurally and magnetically characterized. Complexes 1NO3-3BF4 consist of 1D chains formed by the [Fe(qsal-4-F)2]+ cations connected by π-π and C-H···O interactions, which are further linked by more weak interactions to form 2D layers and 3D networks. On the other hand, complex 4OTf has a structure of nearly isolated 1D column where the [Fe(qsal-4-F)2]+ cations are connected by π-π, C-H···π, and C-F···π interactions. Magnetic studies revealed the occurrence of two-step symmetry-breaking SCO in 1NO3 and two-step gradual SCO in 2PF6. Complex 3BF4 undergoes a gradual SCO, whereas 4OTf remains almost high-spin. The smaller anions tend to stabilize the low-spin state, while larger anions tend to stabilize the high-spin state. In addition, the intermediate spin state of 1NO3 could be thermally trapped by quenching from the high temperature, thereby kinetically suppressing the spin transition to the full low-spin state. This work represents a good example that the position of the substituent and the anions plays critical roles in the preparation of SCO materials with tunable properties.

Practical chemoselective aromatic substitution: the synthesis of N-(4-halo-2-nitrophenyl)benzenesulfonamide through the efficient nitration and halogenation of N-phenylbenzenesulfonamide.

A novel route involving the metal-promoted tandem nitration and halogenation of N-phenylbenzenesulfonamide to synthesize N-(4-halo-2-nitrophenyl)benzenesulfonamide derivatives has been developed. The method shows highly practical chemoselective and functional group compatibility. In addition, it employs insensitive and inexpensive Cu(NO3)2·3H2O, Fe(NO3)3·9H2O, and NH4NO3 as the nitration reagents, and it provides a direct approach for the preparation of 4-halo-2-nitroaniline, which is a crucial intermediate for the synthesis of benzimidazoles and quinoxaline derivatives.

Preparation of a Novel pH-responsive Fluorescent Probe Based on an Imidazo[1,2-a]indole Fluorophore and its Application in Detecting Extremely Low pH in Saccharomyces cerevisiae.

A novel pH-responsive probe based on an imidazo[1,2-a]indole fluorophore architecture is reported. The probe was highly selective to strongly acidic pH (pKa = 3.56) with high sensitivity and a fast response time (within 30 s). The probe did not demonstrate any fluorescence changes in the presence of interfering metal ions, and it featured excellent reversibility under strongly acidic conditions. The mechanism of detection of the probe was determined to be based on intramolecular charge transfer (ICT) at different pH. The probe was also able to be used for imaging for detecting acidic pH in Saccharomyces cerevisiae.

Ruthenium(II)-Catalyzed α-Fluoroalkenylation of Oxime Ethers with gem-Difluorostyrenes via C-H Activation and C-F Cleavage.

A novel route for ruthenium(II)-catalyzed α-fluoroalkenylation of oxime ethers with gem-difluorostyrenes via C-H activation and C-F cleavage has been developed for the first time. Notably, the alkenyl units of products exhibit exclusive Z-configuration. This reaction features a broad substrate scope and good functional group tolerance. A plausible reaction mechanism is confirmed by an available cycloruthenated intermediate. Besides, the O-methyl oximyl-directing group can be readily removed to access the α-fluoroalkenylated acetophenones.

Rhodium(III)-catalyzed C4-amidation of indole-oximes with dioxazolones via C-H activation.

A novel method for the Rh(iii)-catalyzed oxime-directed C-H amidation of indoles with dioxazolones has been developed. This strategy provides an exclusive site selectivity and the directing group can be easily removed. This transformation features a wide substrate scope, good functional group tolerance and excellent yields, and may serve as a significant tool to construct structurally diverse indole derivatives for the screening of potential pharmaceuticals in the future.

Transition-metal free oxidative C-H etherification of acylanilines with alcohols through a radical pathway.

A transition metal free approach for the synthesis of methyl/ethyl aryl ether via oxidative C-H etherification of acylanilines with alcohols has been developed. Various acylanilines are compatible under standard conditions, giving the corresponding products in moderate to good yields. This strategy avoids transition-metal catalyst and excessive alcohol, providing a simple and reliable alternative method for the synthesis of methyl/ethyl aryl ether. Control experiments reveal that a radical mechanism is involved in this transformation.

Transition-metal- and oxidant-free three-component reaction of quinoline N-oxides, sodium metabisulfite and aryldiazonium tetrafluoroborates via a dual radical coupling process.

A convenient and straightforward three-component transformation of quinoline N-oxides, sodium metabisulfite and aryldiazonium tetrafluoroborates has been developed, providing the target products in moderate to good yields. Compared with previous studies, the present methodology avoids the use of transition-metal catalysts and excess oxidants, providing a simple and practical alternative approach for the construction of 2-sulfonylquinolines. Control experiments indicate that a dual radical coupling process is responsible for this reaction.

Copper-mediated direct thiolation of aryl C-H bonds with disulfides.

An efficient copper-mediated ortho-C(sp2)-H thiolation of aromatic amides directed by a novel directing group [4-chloro-2-(1H-pyrazol-1-yl)phenyl]amine has been developed without the need of other additives or oxidants, allowing for an increased usefulness. With the high compatibility of sterically demanding substrates, this reaction is scalable and can tolerate a wide scope of functional groups to provide alkyl and aryl thioethers in good to excellent yields (up to 93%). Furthermore, the protocol has been successfully implemented for the selenylation as well.

Iron-catalyzed ortho trifluoromethylation of anilines via picolinamide assisted photoinduced C-H functionalization.

A convenient, oxidant-free protocol was developed for the ortho trifluoromethylation of aniline via picolinamide assisted Fe-promoted C-H functionalization under ultraviolet irradiation. In this transformation acetone essentially acted as both a solvent to dissolve reactants and a low-cost radical initiator to efficiently generate a CF3 radical from Langlois' reagent. A broad substrate scope was tolerated and picolinamide bearing strong electron withdrawing groups also could be transformed into the corresponding products with acceptable yields. Furthermore, the value of this method has been highlighted via the efficient synthesis of the nonsteroidal anti-inflammatory drug floctafenine.

Selective remote esterification of 8-aminoquinoline amides via copper(ii)-catalyzed C(sp2)-O cross-coupling reaction.

The remote C-O coupling of quinoline amides at the C5 position has been established using cheap and readily available copper catalyst under mild conditions. The positionally selective esterification protocol afforded C-O coupling products in moderate to excellent yields. Most importantly, this method may provide a potential alternative to the existing ways to build functionalized 5-hydroxyquinoline derivatives, which are utilized as pivotal intermediates in the synthesis of drug candidates.

A high-quality haplotype genome of Michelia alba DC reveals differences in methylation patterns and flower characteristics.

Michelia alba DC is a highly valuable ornamental plant of the Magnoliaceae family. This evergreen tropical tree commonly grows in Southeast Asia and is adored for its delightful fragrance. Our study assembled the M. alba haplotype genome MC and MM by utilizing Nanopore ultralong reads, Pacbio Hifi long reads and parental second-generation data. Moreover, the first methylation map of Magnoliaceae was constructed based on the methylation site data obtained using Nanopore data. Metabolomic datasets were generated from the flowers of three different species to assess variations in pigment and volatile compound accumulation. Finally, transcriptome data were generated to link genomic, methylation, and morphological patterns to reveal the reasons underlying the differences between M. alba and its parental lines in petal color, flower shape, and fragrance. We found that the AP1 and AP2 genes are crucial in M. alba petal formation, while the 4CL, PAL, and C4H genes control petal color. The data generated in this study serve as a foundation for future physiological and biochemical research on M. alba, facilitate the targeted improvement of M. alba varieties, and offer a theoretical basis for molecular research on Michelia L.

Iron-Catalyzed Synthesis of Benzosultams from N-Phenyl-N-(prop-2-yn-1-yl)benzenesulfonamide and Benzenesulfonyl Hydrazine.

A novel route for an iron-catalyzed tandem sulfonylation, C(sp2)-H activation, cyclization reaction which uses N-phenyl-N-(prop-2-yn-1-yl)benzenesulfonamide and benzenesulfonohydrazide to synthesize derivatives of (Z)-2-phenyl-4-((phenylsulfonyl)methylene)-3,4-dihydro-2H-benzo[e][1,2]thiazine 1,1-dioxide has been developed. The method features convenient operation and good functional group tolerance. In addition, it employs insensitive and inexpensive FeSO4 as the catalyst and provides a direct approach for the preparation of benzothiazides.

Establishment of environment-sensitive probes targeting BRD3/BRD4 for imaging and therapy of tumor.

The BET (bromo and extra-terminal) family proteins are epigenetic readers and master transcription coactivators, which have attracted great interests as cancer therapeutic targets. However, there are few developed labeling toolkits that can be applied for the dynamic studies of BET family proteins in living cells and tissue slices. In order to label and study the distribution of the BET family proteins in tumor cells and tumor tissues, a novel series of environment-sensitive fluorescent probes (6a-6c) were designed and evaluated for their labeling properties. Interestingly, 6a is capable of identifying tumor tissue slices and making a distinction between the tumor and normal tissues. Moreover, it can localize to the nuclear bodies in tumor slices just like BRD3 antibody. In addition, it also played an anti-tumor role through the induction of apoptosis. All these features render 6a may compatible for immunofluorescent studies and future cancer diagnosis, and guide for the discovery of new anticancer drugs.