摘要
用异烟酸(Iso-NTA)为桥接分子,将有机小分子自由基4-氨基-2,2,6,6-四甲基哌啶-1-氧自由基(4-NH 2-TEMPO)与异烟酸缩合,合成出含吡啶官能团的TEMPO自由基(Iso-NTA-TEMPO).与TEMPO相比,Iso-NTA-TEMPO具有较高的氧化电位,在无Cu(Ⅱ)辅助时,Iso-NTA-TEMPO对苯甲醇的氧化效率高于TEMPO.在与HKUST-1组成的复合催化体系中,Iso-NTA-TEMPO可通过吡啶基团与HKUST-1孔道中的Cu(Ⅱ)相互作用,从而在催化过程中(部分)锚定在HKUST-1孔道内部.与TEMPO/HKUST-1体系相比,Iso-NTA-TEMPO/HKUST-1体系表现出对芳香醇更加高效的催化活性.采用模板辅助溶剂诱导结晶法合成的HKUST-1晶体表面具有较多缺陷,更有利于Iso-NTA-TEMPO自由基分子扩散进入HKUST-1孔道内部,也有助于提高Iso-NTA-TEMPO/HKUST-1体系的催化效率.Iso-NTA-TEMPO/HKUST-1体系可将各种取代基(苄醇、杂环醇以及二级脂肪醇)高效、高选择性地氧化成相应的醛或酮.
By using isonicotinic acid(Iso-NTA)as a bridging molecule,a pyridyl functionalized 2,2,6,6-tetramethylpiperidinyl-1-oxy(TEMPO)radical(Iso-NTA-TEMPO)was synthesized by the condensation of 4-amino-2,2,6,6-tetramethylpiperidino-1-oxy(4-NH 2-TEMPO)and isonicotinic acid.Compared with TEMPO,Iso-NTA-TEMPO exhibited higher oxidation potential,which facilitates the oxidation reaction of benzyl alcohol,without the use of Cu(Ⅱ).In the case of Iso-NTA-TEMPO/HKUST-1 hybrid catalytic system,the Iso-NTA-TEMPO can be(partially)coordinated to Cu(Ⅱ)sites of HKUST-1 by pyridyl group during catalysis.As consequence,the Iso-NTA-TEMPO/HKUST-1 catalytic system shows much higher catalytic activity than that of TEMPO/HKUST-1 system,toward the oxidation of aromatic alcohols.Moreover,HKUST-1 synthesized by template assisted solvent-induced crystallization consists a significant amount of defects,which facilitates the diffusion of Iso-NTA-TEMPO into the pores of HKUST-1,thus,improving the catalytic activity of Iso-NTA-TEMPO/HKUST-1.The Iso-NTA-TEMPO/HKUST-1 system enables the oxidation of a broad range of primary aromatic alcohols with various substituted groups and heteroatoms,as well as secondary aliphatic alcohols with high efficiency and selectivity.
作者
薛云
晏秘
申妍铭
毛会玲
王晨
程琥
庄金亮
XUE Yun;YAN Mi;SHEN Yanming;MAO Huiling;WANG Chen;CHENG Hu;ZHUANG Jinliang(Key Laboratory of Functional Materials and Chemistry of Guizhou Province,School of Chemistry and Materials Science,Guizhou Normal University,Guiyang 550001,China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第5期1068-1075,共8页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:21861013)
贵州省科技厅基金(批准号:[2016]1413,[2018]5769)
贵州省普通高等学校科技拔尖人才支持计划项目(批准号:黔教合KY字[2017]063)资助.
