No abstract

Selective C­(sp3)–H isothiocyanation represents a significant strategy for the synthesis of isothiocyanate derivatives. We report herein an electrochemical benzylic isothiocyanation in a highly chemo- and site-selective manner under external oxidant-free conditions. The high chemoselectivity is attributed to the facile in situ isomerization of benzylic thiocyanates to isothiocyanates. Notably, the method exhibits high functional group compatibility and is suitable for late-stage functionalization of bioactive molecules.

The rapid development and popularization of the network have brought many problems to network security. Intrusion detection technology is often used as an effective security technology to protect the network. The deep belief network (DBN), as a classic model of deep learning, has good classification performance and is often used in the field of intrusion detection. However, the network structure of DBN is generally set through practical experience. For the optimization problem of the DBN-based intrusion detection classification model (DBN-IDS), this paper proposes a new joint optimization algorithm to optimize the DBN's network structure. First, we design a particle swarm optimization (PSO) based on the adaptive inertia weight and learning factor. Second, we use the fish swarm behavior of cluster, foraging, and other behaviors to optimize the PSO to find the initial optimization solution. Then, based on the initial optimization solution, we use the genetic operators with self-adjusting crossover probability and mutation probability to optimize the PSO to search the global optimization solution. Finally, the global optimization solution constructed by the above-mentioned joint optimization algorithm is used as the network structure of the intrusion detection classification model. The experimental results show that compared with other DBN-IDS optimization algorithms, our algorithm shortens the average detection time by at least 24.69% on the premise of increasing the average training time by 6.9%; compared with the tested classification algorithms, our DBN-IDS improves the average classification accuracy by at least 1.3% and up to 14.80% in the five-category classification, which is proved to be an efficient DBN-IDS optimization method. INDEX TERMS Intrusion detection, deep belief network, particle swarm optimization, artificial fish swarm algorithm, genetic algorithm.

On account of the broad utilities of organophosphorus compounds, the development of highly efficient and concise phosphination methods is significantly important and urgent. Herein, we disclose a novel method for the synthesis of phosphorylated heterocycles: versatile intermediate propargylamines serving as a new type of radical acceptors incorporated in P-radicals via a photocatalytic strategy. This reaction proceeds through a cascade phosphinoylation/cyclization/oxidation/aromatization pathway using readily available starting materials under mild conditions of light with excellent atom economy, catalyzed by AgOAc or fac-Ir(ppy). One of the phosphorylated quinolines was selected, as an example, as an electron-transporting material for fabricating phosphorescence organic light-emitting diodes displaying excellent electroluminescence performances with a maximum external quantum efficiency of 21.9% with negligible efficiency roll-off ratios.

Mobile glucose-pesticide conjugates in the phloem are often restricted by decreases in biological activity. However, plants can bioactivate endogenous glucosides, which are assumed as able to bioactivate exogenous conjugates. In this study, four glycosidic bonds (O-, S-, N-, and C-glycosidic bonds) of glucose-pesticide conjugates were designed and synthesized, and then metabolism assays were carried out in vitro and in vivo. Results showed that β-glucosidases played a role in the hydrolysis of O-glycosidic bond conjugates in Ricinus communis L. The liberated aglycons possessed insecticidal activities against Plutella xylostella L. and Spodoptera litura F. These results could help establish methods of circumventing the mutual exclusivity of phloem mobility and biological activity by hydrolyzing endogenous β-glucosidases.