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Fluoroalcohol-mediated reductive iodonio-Claisen rearrangement: Synthesis of complex

Hem Raj Khatri,Hai Nguyen,James K. Dunaway,Jianglong Zhu

《化学科学与工程前沿（英文）》 2015年第9卷第3期页码 359-368 doi: 10.1007/s11705-015-1530-6

摘要： Reductive iodonio-Claisen rearrangement (RICR) involving -iodanes and allyl or substituted-allyl silanes in fluoroalcohols, such as 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and 2,2,2-trifluoroethanol (TFE), was studied for the synthesis of complex -allyl or substituted-allyl iodoarenes. In comparison to the previously reported condition involving boron trifluoride diethyl etherate, the RICR mediated by fluoroalcohols was found to proceed more effectively. The resulting complex -allyl iodoarenes are useful synthetic intermediates and can be readily converted to various heterocyclic compounds.

关键词： hypervalent iodine allylation fluoroalcohol Claisen rearrangement heterocycles

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Influence of Na

Rumin YANG, Fanhui MENG, Xiao WANG, Yaquan WANG

《化学科学与工程前沿（英文）》 2011年第5卷第4期页码 401-408 doi: 10.1007/s11705-011-1129-5

摘要： Silicalite-1 was hydrothermally synthesized in the presence of different concentrations of Na using tetrapropylammonium hydroxide (TPAOH) as a template. The synthesis was followed by a base treatment. The silicalite-1samples were characterized using X-ray diffraction, scanning electron microscopy, N adsorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and NH temperature-programmed desorption. The samples were used as catalysts for the vapor phase Beckmann rearrangement of cyclohexanone oxime. During the synthesis, the sodium ions were incorporated onto the silicalite-1 crystals, but were then removed by the base treatment. All the catalysts exhibited nearly complete conversion of cyclohexanone oxime to ?-caprolactam with selectivities grater than 95%. Addition of less than 2.5 mol-% Na (relative to TPAOH) did not influence the catalytic properties. However, for Na concentrations≥5 mol-%, the particle sizes of silicalite-1 increased and the catalytic activities decreased, which can be attributed to carbon deposition. The results in this work are of great importance for the polymer industry.

关键词： silicalite-1 cyclohexanone oxime vapor phase Beckmann rearrangement ?-caprolactam

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Efficient controller area network data compression for automobile applications

Yu-jing WU,Jin-Gyun CHUNG

《信息与电子工程前沿（英文）》 2015年第16卷第1期页码 70-78 doi: 10.1631/FITEE.1400136

摘要： Controller area networks (CANs) have been designed for multiplexing communication between electronic control units (ECUs) in vehicles and many high-level industrial control applications. When a CAN bus is overloaded by a large number of ECUs connected to it, both the waiting time and the error probability of the data transmission are increased. Thus, it is desirable to reduce the CAN frame length, since the duration of data transmission is proportional to the frame length. In this paper, we present a CAN message compression method to reduce the CAN frame length. Experimental results indicate that CAN transmission data can be compressed by up to 81.06% with the proposed method. By using an embedded test board, we show that 64-bit engine management system (EMS) CAN data compression can be performed within 0.16 ms; consequently, the proposed algorithm can be successfully used in automobile applications.

关键词： Controller area network (CAN) Electronic control units (ECUs) Data compression Signal rearrangement

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Conserved gene arrangement in the mitochondrial genomes of barklouse families Stenopsocidae and Psocidae

Xiaochen LIU, Hu LI, Yao CAI, Fan SONG, John-James WILSON, Wanzhi CAI

《农业科学与工程前沿（英文）》 2017年第4卷第3期页码 358-365 doi: 10.15302/J-FASE-2017158

摘要： Substantial variation in gene organization and arrangement has been reported for sequenced mitochondrial (mt) genomes from the suborders of the insect order Psocoptera. In this study we sequenced the complete mt genome of , the first representative of the family Stenopsocidae from the suborder Psocomorpha. Relative to the ancestral pattern, rearrangements of a protein-coding gene ( ) and five tRNA genes ( , , , , ) were found. This pattern was similar to that of two barklice from the family Psocidae, with the exception of the translocation of , and Based on comparisons of pairwise breakpoint distances of gene rearrangements, gene number and chromosome number, it was concluded that mt genomes of Stenopsocidae and Psocidae share a relatively conserved pattern of gene rearrangements; mt genomes within the Psocomorpha have been generally stable over long evolutionary history; and mt gene rearrangement has been substantially faster in the booklice (suborder Troctomorpha) than in the barklice (suborders Trogiomorpha and Psocomorpha). It is speculated that the change of life history and persistence of unusual reproductive systems with maternal inheritance contributed to the contrasting rates in mt genome evolution between the barklice and booklice.

关键词： gene rearrangement mitochondrial genome Psocoptera Stenopsocidae TDRL model

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Improving prodeoxyviolacein production via multiplex SCRaMbLE iterative cycles

Juan Wang, Bin Jia, Zexiong Xie, Yunxiang Li, Yingjin Yuan

《化学科学与工程前沿（英文）》 2018年第12卷第4期页码 806-814 doi: 10.1007/s11705-018-1739-2

摘要：

The synthetic chromosome rearrangement and modification by loxP-mediated evolution (SCRaMbLE) system has been used to improve prodeoxyviolacein (PDV) production in haploid yeast containing chromosome synV. To rapidly and continuously generate genome diversification with the desired phenotype, the multiplex SCRaMbLE iterative cycle strategy has been developed for the screening of high PDV production strains. Whole-genome sequencing analysis reveals large duplications, deletions, and even the whole genome duplications. The deletion of YER151C is proved to be responsible for the increase. This study demonstrates that artificial DNA rearrangement can be used to accelerate microbial evolution and the production of biobased chemicals.

关键词： synthetic biology genome rearrangement prodeoxyviolacein SCRaMbLE Saccharomyces cerevisiae