有机化学 ›› 2024, Vol. 44 ›› Issue (6): 1957-1966.DOI: 10.6023/cjoc202311013 上一篇    下一篇

研究论文

苯并唑-氮杂环卡宾钯配合物的合成表征及应用

孙超a,b, 周泉b,*(), 李传莹a,*(), 王磊b,c,d,*()   

  1. a 浙江理工大学化学系 杭州 310018
    b 台州学院高研院和药学院 浙江台州 318000
    c 杭州师范大学 有机硅化学及材料技术教育部重点实验室 杭州 311121
    d 中国科学院上海有机化学研究所 金属有机化学国家重点实验室 上海 200032
  • 收稿日期:2023-11-14 修回日期:2024-01-29 发布日期:2024-02-27
  • 基金资助:
    国家自然科学基金(22071171); 浙江省自然科学基金(LZ22B020003)

Syntheses and Structural Characterizations of Benzoxazolyl N-Heterocyclic Carbene-Palladium Complexes and Their Applications

Chao Suna,b, Quan Zhoub,*(), Chuanying Lia,*(), Lei Wangb,c,d,*()   

  1. a Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018
    b Advanced Research Institute & School of Pharmaceutical Sciences, Taizhou University, Taizhou, Zhejiang 318000
    c Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Hangzhou 311121
    d State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032
  • Received:2023-11-14 Revised:2024-01-29 Published:2024-02-27
  • Contact: * leiwang@chnu.edu.cn; qzhou@tzc.edu.cn; licy@zstu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(22071171); Natural Science Foundation of Zhejiang Province(LZ22B020003)

合成了6个具有柔性直链烷基或苄基连接体的七元苯并噁唑-氮杂环卡宾钯的新配合物, 用NMR, HRMS, FTIR等对其构进行了表征, 并用X射线单晶衍射进一步确认了其中3个配合物的结构. 晶体解析显示钯配位中心是稍微扭曲的平面四边形构型, 其配体中苯并噁唑和氮杂环卡宾平面互成一定角度, 不共平面. 氮杂环卡宾片段相连的第一个亚甲基上的偕二氢在配合物中表现磁各向异性, 亚甲基偕二氢化学位移差(Δδg)随侧链长度增长而变化, 侧链为四个碳的直链烷基时, Δδg最大. 催化活性应用研究显示, 此类配合物对Suzuki-Miyaura反应具有优异的催化活性, 并且可应用于两步一锅法合成联苯类偕二氟烯烃化合物.

关键词: 氮杂环卡宾钯, Suzuki-Miyaura偶联, 偕二氟烯烃

Six seven-membered benzoxazolyl N-heterocyclic carbene (Benzoxa^NHC) palladium complexes with flexible linear alkyl or benzyl linkers were synthesized. Their structures were characterized by NMR, HRMS, and FTIR spectroscopies. The structures of three complexes were further confirmed by X-ray single crystal diffraction. Palladium center adopted slight distorted square planer geometry, and the benzoxazole and NHC planes in its ligand formed a certain angle with each other, not coplanar. The first methylene group connected to a nitrogen-containing heterocyclic carbene fragment exhibited magnetic anisotropy in the complex. The shift difference in the methylene group (Δδg) changed with the increase of the length of the side chain. When the side chain was a linear chain alkyl group of four carbons, Δδg reched maximum. Furthermore, these complexes showed excellent catalytic performance in Suzuki-Miyaura coupling, and could be used to synthesize biphenyl gem-difluoroethenes in the manner of two steps in one pot.

Key words: N-heterocyclic carbene-palladium complex, Suzuki-Miyaura reaction, gem-difluoroalkene