A dehydroxylative ring-opening Giese reaction of cyclobutanone oximes enabled by photoredox/Ti dual catalysis has been reported in this work.This protocol avoids the prefunctionalization of oximes and the use of stoic...A dehydroxylative ring-opening Giese reaction of cyclobutanone oximes enabled by photoredox/Ti dual catalysis has been reported in this work.This protocol avoids the prefunctionalization of oximes and the use of stoichiometric triarylphosphine reagents.It also features mild conditions,broad substrate scope and good functional group tolerance.The gram-scale reaction,product derivatization,late-stage functionalization of complex pharmaceutical and natural product derivatives,and oligopeptide modification exhibit the potential application of this methodology in synthetic chemistry.展开更多
采用热重分析法对煤矸石中高岭石的脱羟基特点进行研究,结合X射线衍射对煤矸石煅烧后的晶相组成进行分析,运用Coats and Redfern方法研究煤矸石中高岭石的脱羟基动力学.结果表明,煤矸石中高岭石脱羟基反应发生的温度区间为400℃～800℃,...采用热重分析法对煤矸石中高岭石的脱羟基特点进行研究,结合X射线衍射对煤矸石煅烧后的晶相组成进行分析,运用Coats and Redfern方法研究煤矸石中高岭石的脱羟基动力学.结果表明,煤矸石中高岭石脱羟基反应发生的温度区间为400℃～800℃,在650℃左右达到脱羟基的最大失重率,且随着升温速率的增加,最大失重率所对应的温度向高温偏移;650℃,1h煤矸石煅烧样中,高岭石的衍射峰全部消失,完成了高岭石向偏高岭石的相转变;[（1-y）-1/3-1]2机理函数与实验数据吻合较高,且表观活化能EA为231.55kJ/mol,指前因子A为3×1011 s-1。展开更多
The calcining process was recorded by differential scanning calorimetry and ther-mogravimetry （DSC-TG）. The dehydroxylation （activating process） was partitioned into two steps by calculating and comparing the O-H ...The calcining process was recorded by differential scanning calorimetry and ther-mogravimetry （DSC-TG）. The dehydroxylation （activating process） was partitioned into two steps by calculating and comparing the O-H bond lengths between inner hydroxyl group and surface hydroxyl group, as well as the ionic bond of Al-OH and position of -OH. X-ray diffraction （XRD） and compressive strength measurement show that the activity of calcined materials increases with the increasing of temperature in dehydroxylation region but decreases abruptly in the ＂spinel＂ region. The suggested temperature for activating kaolinite is 900 ℃ .展开更多
基金grateful for the financial support from the National Natural Science Foundation of China(Nos.22101135 and 21502096)the Natural Science Foundation of Jiangsu Province(No.BK20150652)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.KYQN2022058,KJQN201629 and XUEKEN2022032)“333 High-Level Talent Project”of Jiangsu Province.
文摘A dehydroxylative ring-opening Giese reaction of cyclobutanone oximes enabled by photoredox/Ti dual catalysis has been reported in this work.This protocol avoids the prefunctionalization of oximes and the use of stoichiometric triarylphosphine reagents.It also features mild conditions,broad substrate scope and good functional group tolerance.The gram-scale reaction,product derivatization,late-stage functionalization of complex pharmaceutical and natural product derivatives,and oligopeptide modification exhibit the potential application of this methodology in synthetic chemistry.
文摘采用热重分析法对煤矸石中高岭石的脱羟基特点进行研究,结合X射线衍射对煤矸石煅烧后的晶相组成进行分析,运用Coats and Redfern方法研究煤矸石中高岭石的脱羟基动力学.结果表明,煤矸石中高岭石脱羟基反应发生的温度区间为400℃～800℃,在650℃左右达到脱羟基的最大失重率,且随着升温速率的增加,最大失重率所对应的温度向高温偏移;650℃,1h煤矸石煅烧样中,高岭石的衍射峰全部消失,完成了高岭石向偏高岭石的相转变;[（1-y）-1/3-1]2机理函数与实验数据吻合较高,且表观活化能EA为231.55kJ/mol,指前因子A为3×1011 s-1。
基金Funded by the National High-Tech Research and Development Programof China(No. 2006AA06Z225)
文摘The calcining process was recorded by differential scanning calorimetry and ther-mogravimetry （DSC-TG）. The dehydroxylation （activating process） was partitioned into two steps by calculating and comparing the O-H bond lengths between inner hydroxyl group and surface hydroxyl group, as well as the ionic bond of Al-OH and position of -OH. X-ray diffraction （XRD） and compressive strength measurement show that the activity of calcined materials increases with the increasing of temperature in dehydroxylation region but decreases abruptly in the ＂spinel＂ region. The suggested temperature for activating kaolinite is 900 ℃ .
