A synthetic method to construct boron-handled cyclic molecules was developed based on a radical borylation/cyclization cascade of 1,6-enynes. The process initiated by the chemo- and regio-controlled addition an N-heterocyclic carbene-boryl alkene or alkyne, followed ring closure afford boron-substituted skeletons. Further molecular transformations products synthetically useful building blocks were also demonstrated.

Radical borylation using N-heterocyclic carbene (NHC)-BH3 complexes as boryl radical precursors has emerged an important synthetic tool for organoboron assembly. However, the majority of reported methods are limited to reaction modes involving carbo- and/or hydroboration specific alkenes and alkynes. Moreover, generation NHC-boryl radicals relies principally on hydrogen atom abstraction with aid initiators. A distinct method is reported, well pathways enabled by photoredox catalysis....

Reverse to success! A new formal [3+2] annulation reaction combining alkynyl aldehydes and β,γ-unsaturated α-ketoesters has been disclosed by using a NHC-catalyzed/Lewis acid mediated strategy. This cooperative catalysis strategy first allows the "allenolate" intermediate as nucleophilic synthon at β-position react with activated electrophilic reagents an addition key CC bond-forming step. As service our authors readers, this journal provides supporting information supplied authors. Such...

A strategy for the NHC-catalyzed synthesis of dihydropyridinones and spirooxindoles has been developed via [3+3] annulation reactions enals or isatin-derived with 2-aminoacrylates under oxidative conditions. In this efficient strategy, served as nucleophiles. Modifying standard base switched carbon-carbon double bond formation from 5,6-positions to 3,4-positions generate 5,6-dihydropyridinones 3,4-dihydropyridinones, respectively. Meanwhile, a diverse set spirooxindole derivatives were also...

Abstract A radical azidomethylation of various alkenes with azidotrimethylsilane and dimethyl sulfoxide has been achieved under mild reaction conditions, the method efficiently introduces common valuable azide methyl groups into organic compounds. It offers a convenient for preparing azides, which can be easily transformed related amine derivatives N ‐heterocycles. Control experiments such as capturing intermediate gram‐scale reactions developed system well further transformations products...

A radical borylative cyclization reaction of 1,6-dienes was developed to assemble boron-handled six-membered heterocycles and carbocycles. This initiated by the chemo- regio-controlled addition an N-heterocyclic carbene–boryl one alkene tethers, followed intramolecular 6-exo afford a ring framework. The utility this method demonstrated in synthesis diverse paroxetine analogues through late-stage derivatization boryl functional unit.

Abstract We have developed an N ‐heterocyclic carbene (NHC)‐catalyzed [3+3] annulation of α,β−γ,δ‐unsaturated aldehydes with enamines for the asymmetric synthesis dihydropyridinone that bearing all‐carbon quaternary center. This strategy proceeding via NHC‐mediated γ,δ–protonation α,β−γ,δ−unsaturated aldehydes, followed by cycloadditions. protocol delivers a wide range substituited dihydropyridinones in good yields excellent enantioselectivities.

Abstract. The Shanggong Au deposit in the Xiong'er Terrane, East Qinling, has reserves of about 30 t Au, making it one largest orogenic‐type deposits hosted volcanic rocks China. is andesitic assemblage Group 1.85˜1.4 Ga. Three stages hydrothermal ore‐forming processes are recognized, Early (E), Middle (M) and Late (L), characterised by quartz‐pyrite, polymetallic sulfides carbonate‐quartz, respectively. Homogenization temperatures fluid inclusions between 380‐320d̀C for E‐stage, 300‐220d̀C...

The methylation or trideuteromethylation reaction of isocyanides with dimethyl sulfoxides in a radical way is developed, which offers low-cost, easy-operation cascade strategy for the synthesis phenanthridines isoquinolines.

A NHC-catalyzed [3+3] annulation of enals with pyrrol-4-ones was developed, thus providing various dihydropyrano[3,2-<italic>b</italic>]pyrrol-5-ones broad scope and excellent enantioselectivities.

An N-heterocyclic carbene-catalyzed atroposelective [3 + 3] annulation of enals with 2-aminomaleate derivatives is described. A series substituted dihydropyridones bearing both C-N axis and point chirality were synthesized good diastereo- enantioselectivity under mild conditions. This efficient strategy successfully superpositions an extra chiral element axial backbone, the generated structurally interesting atropisomers may have potential application in drug discovery.

An enantioselective construction of pyrazolo[3,4-b]pyridones was achieved via N-heterocyclic carbene-catalyzed [3 + 3] annulation enals with 5-aminopyrazoles. This protocol not only offers a highly efficient synthetic approach for the preparation various substituted but also provides an effective method rapid synthesis enantiopure spirooxindone derivatives.

N-Heterocyclic carbene-catalyzed formal [3+2] annulation of alkynyl aldehydes and nitrosobenzenes has been reported. This transformation provided the novel C–X bond formation under mild conditions in moderate to satisfactory yields. The catalytic protocol allows for a rapid construction 2,5-disubstituted isoxazol-3(2H)-ones 2,3-disubstituted isoxazol-5(2H)-ones from same materials via highly regioselectively umpolung stratgy.

N-Heterocyclic carbene was employed as an efficient organic catalyst to catalyze a cascade epoxide-opening and lactonization reaction. This organocatalytic process could transform various readily accessible γ-epoxy-α,β-enals into dihydropyrone derivatives in good excellent yields.

A novel and convenient strategy for the enantioselective synthesis of γ-lactam derivatives via N-heterocyclic carbene catalyzed formal [3 + 2] annulation enals with 2-aminoacrylates is disclosed. This activation mode provides a complementary approach to various in good yields excellent diastereo- enantioselectivities. In this process, two consecutive stereocenters are constructed, quaternary carbon center also established.

ABSTRACT Quantitative analysis of activated neurons in mouse brains by a specific stimulation is usually primary step to locate the responsive throughout brain. However, it challenging comprehensively and consistently analyze neuronal activity trace whole large cohort mice from many terabytes volumetric imaging data. Here, we introduce NEATmap, deep learning–based high-efficiency, high-precision user-friendly software for whole-brain mapping automated segmentation quantitative...

作为对基于密码体系的安全手段的重要补充,信任管理在解决WSNs(wireless sensor networks)中的内部攻击,识别恶意节点、自私节点及低竞争力节点,提高系统安全性、可靠性和公平性等方面有着显著优势.综述了WSNs环境下信任管理的特点、分类方法、框架设计、脆弱性分析、攻击模型及对策,在此基础上介绍了WSNs下的典型信任管理系统.以信任计算模型为中心的WSNs环境下信任管理框架的设计是信任管理系统的核心,从信任要素、信任计算模型和信任值的应用这3个方面对其进行了深入讨论.最后,总结了WSNs环境下信任管理的研究现状,提出了值得参考的研究发展方向.;Cryptography based security solutions are not enough for WSNs when there attacks from interior, which caused by compromised nodes. Trust management can deal with this problem efficiently, and enhance the...

An efficient total synthesis of (-)-bitungolide F (6) in 17 steps and 20.1% yield is described herein. Key involve a Myers asymmetric alkylation to introduce the C6 methyl with proper stereochemistry, Claisen-like cyclization construct alpha,beta-unsaturated delta-lactone Julia-Kocienski olefination assemble conjugated diene moiety.

An NHC-catalyzed enantioselective [3 + 2] annulation of enals and isoindigo is introduced as an efficient strategy for the construction dimeric spirocyclic bisindoline alkaloid derivatives with moderate yields good enantioselectivities.

An NHC-catalyzed enantio- and diastereoselective [3 + 2] annulation of α-bromoenals with bisoxindoles is developed, affording efficient access to various spirocyclic bisoxindole alkaloids. This protocol tolerates a broad substrates scope, obtained in generally excellent enantioselectivities. More importantly, two contiguous sterically congested all-carbon quaternary stereocenters are successfully created during this process.