Chinese Journal of Organic Chemistry ›› 2023, Vol. 43 ›› Issue (1): 265-273.DOI: 10.6023/cjoc202205038 Previous Articles     Next Articles



熊威a, 石斌a, 姜烜a, 陆良秋a,b,*(), 肖文精a   

  1. a 华中师范大学化学学院 武汉 430079
    b 河南师范大学化学化工学院 河南新乡 453007
  • 收稿日期:2022-05-22 修回日期:2022-07-25 发布日期:2022-08-17
  • 通讯作者: 陆良秋
  • 基金资助:
    国家自然科学基金(21822103); 国家自然科学基金(21820102003); 国家自然科学基金(91956201); 高等学校学科创新引智计划(111计划); 高等学校学科创新引智计划(B17019); 湖北省自然科学基金(2017AHB047)

Ligand-Switched Pd-Catalyzed Divergent Transformations of Vinyl Cyclic Carbamates and Isocyanates

Wei Xionga, Bin Shia, Xuan Jianga, Liangqiu Lua,b(), Wenjing Xiaoa   

  1. a College of Chemistry, Central China Normal University, Wuhan 430079
    b School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007
  • Received:2022-05-22 Revised:2022-07-25 Published:2022-08-17
  • Contact: Liangqiu Lu
  • Supported by:
    National Natural Science Foundation of China(21822103); National Natural Science Foundation of China(21820102003); National Natural Science Foundation of China(91956201); Program of Introducing Talents of Discipline to Universities of China (111 Program); Program of Introducing Talents of Discipline to Universities of China(B17019); Natural Science Foundation of Hubei Province(2017AHB047)

Synthesis of urea compounds is highly significant for pharmaceutical chemistry, agricultural chemistry, matterials science and organic synthesis. By ultilizing ligands to switch the chemoselectivity, two transformations of vinyl cyclic carbamates and isocyanates were developed to afford linear and cyclic ureas in a controlled manner. When phosphoramidite was used as the monodentate P-ligand, a wide range of (E)-1,3-diene-substituted linear ureas were produced in high yields and selectivity (21 examples, 51%~95% yields). While, using bidentate biphosphine ligand to replace the phosphoramidite ligand, a variety of highly functionalized vinyl-substitued cyclic ureas, tetrahydro-2-pyrimidinones, were delivered instead starting from the same chemical feedstocks (8 examples, 72%~94% yields). To illusrate the switched chemoselectivity, two possible reaction mechanisms were proposed based on the experiment results and proceeding literatures. The keys of these two reactions, dienylation and annulation, are the β-hydride elimination and the N-allylic alkylation of ally-Pd species, respectively. It is supposed that the basicity of the ligand will affect the reactivity of π-ally-Pd intermediates toward electrophilic ring closing. It is believed that this research not only enriches the application of vinyl carbamate reagents in organic synthesis, but also provides a new protocol to access significant nitrogen-containing molecules.

Key words: ligand-switched, palladium catalysis, urea, vinyl carbamate, isocyanate