Carbonylation of o-arylanilines utilizing CO2 as a carbonyl source for the synthesis important phenanthridinones with free (NH)-lactam motif has been described under metal-free condition. A range were transformed to corresponding in high yields.

Land surface temperature (LST) captures fundamental information on the spatiotemporal variation of energy balance at surface. The trade-off between spatial and temporal resolutions remote sensing images (retrieved LSTs), however, restricts fine-scale thermal environmental investigations. In this context, a novel dual-layer composite framework (DCF) for LST downscaling coupling autocorrelation heterogeneity was developed based two laws geography used to improve existing kernel-driven methods....

Little evidence is available about the association between temperature and cerebrovascular mortality in China. This study aims to examine effects of ambient on different climatic zones China.We obtained daily data weather conditions, air pollution deaths from five cities (Beijing, Tianjin, Shanghai, Wuhan, Guangzhou) China during 2004-2008. We examined city-specific associations mortality, while adjusting for season, long-term trends, day week, relative humidity pollution. cold using a 1°C...

Metal-catalyzed direct deoxygenative C(sp3)–C(sp2) coupling of alcohols is synthetically appealing, but it remains a particular challenge for the synthetic community. Herein, we demonstrate radical dehydroxylative vinylation reaction tertiary by Ti catalysis and, thus, establish method construction vinylated all-carbon quaternary centers. The proceeds under mild conditions and tolerates various functionalities, including Ar–Bpin, Ar–SiMe3, alkyl chloride, phenol, nitrile, ester, furan,...

Abstract An unprecedented asymmetric Diels–Alder reaction of 2‐vinylindoles with methyleneindolinones has been disclosed. Under bifunctional organocatalysis by cinchona‐derived squaramide catalyst, a series diversely functionalized carbazolespirooxindole derivatives bearing three contiguous stereocenters are rapidly constructed under mild conditions (48–90% yields, up to >20:1 dr and 99% ee ). magnified image

The deployment of LoRa networks necessitates joint performance optimization, including packet delivery rate, energy efficiency, and throughput. Additionally, multiple parameters for transmission must be dynamically configured to tailor the metrics prioritization across varying channel environments. Because coupling relationship between metrics, existing works have opted focus on certain or specific circumvent intricate relationship, leading limited adaptability. Therefore, we propose D-LoRa,...

C-Glycosides are valuable structural motifs in bioactive natural products and pharmaceuticals due to their enhanced metabolic stability. However, direct C-glycosylation of native saccharides remains a significant challenge both the inert nature C–OH bond inherent selectivity issues arising from multiple hydroxyl groups. In this SYNPACTS article, we highlight our recent development titanium-catalyzed radical strategy that enables selective activation without prefunctionalization. By...

Radical C-glycosylation presents a flexible and efficient method for synthesizing C-glycosides. Existing methods always require multistep processes generating anomeric radicals. In this study, we introduce streamlined approach to produce radicals through direct C-OH bond homolysis of unmodified saccharides, eliminating the need protection, deprotection, or activation steps. These selectively couple with activated alkenes, yielding products high stereoselectivity (>20:1). This is applicable...

Lewis base promoted selective reduction of CO 2 into boryl formates by using BH 3 NH as a reductant under mild conditions has been reported. The formates, generated in situ, were shown to be reactive and versatile sources formyl compounds create new C–N, C–O, C–C bonds. reactivity the yield formic acid, formamides, secondary alcohols, benzoheterocyclic rings was investigated.

Analysis of glycans by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is usually limited the intrinsically low abundance and ionization efficiency glycans. Aiming to enhance simplify sample preparation procedure during MALDI-MS analysis, we reported herein a novel reactive matrix, 2-phenyl-3-(p-aminophenyl) acrylonitrile (PAPAN), for sensitive selective detection PAPAN derivative α-cyanocinnamic acid, which possesses high in MALDI-MS. The can react with terminal...

An ynamide-mediated one-pot, two-step intermolecular esterification via the condensation of carboxylic acids with nucleophilic hydroxyl species was reported. A broad substrate scope respect to acids, alcohols, and phenols observed. The α-acyloxyenamide intermediates formed by addition ynamides proved be effective acylating reagents for alcohol phenol derivatives assistance base catalysis. Notably, racemization α-chiral center can avoided.

The C-band synthetic aperture radar (SAR) observation is one of the most popular sources for high-resolution tropical cyclone (TC) wind speed estimation. scarcity high data with good quality restricts inversion accuracy speed. It a challenge to obtain high-precision model sparse points. In this paper, TC successfully estimated from dual-polarization SAR signal. Firstly, training dataset total 327 points formed using Sentinel-1A EW/IW mode images and their temporal-spatial matched Stepped...

This paper proposed a graphical and statistical features-based broad learning system (GSF-BLS) to detect tropical cyclogenesis with the Cross-Calibrated Multi-Platform version 2.0 (CCMP V2.0) wind products. The framework of model is composed three modules: data preprocessing module, feature extraction basis (BLS). At stage preprocessing, we use CCMP V2.0 match best tracks Global Tropical Cloud Cluster obtain developed undeveloped samples. stage, convolution module pre-trained weights used...

In this paper we present a novel efficient energy-aware approach for clustering nodes in wireless sensor networks. We use different cluster head (CH) declaration delays each node to characterize the qualification be CH. The guarantees fairly uniform distribution while incurring low overheads. Additionally, do not make any assumptions about or capabilities, e.g., location-awareness. simulation results show that our outperforms LEACH both characteristics and efficiency of prolonging network lifetime.

In this work, we are interested in the compressive sensing of sparse signals whose significant coefficients distributed asymmetrically with respect to zero. To properly address problem, develop a framework utilizing two-state normal and skew mixture density as prior distribution signal. The insignificant signal represented by distributions, respectively. A novel approximate message passing-based algorithm is developed estimate from its compressed measurements. fast gradient-based estimator...

Synthetic aperture radar (SAR) has been proven to be a useful tool in monitoring hurricane structure and intensity. By far, SAR is the most promising spaceborne sensor obtain high-resolution wind field on ocean surface. In this article, an improved asymmetric parametric (IMAHP) model proposed reconstruct speed, where cross-polarization imagery used determine value of parameters. Compared with other models, new can better speed more concise function. For verification, taking SAR-retrieved as...