1612154-01-4Relevant articles and documents
Controllable Site-Selective Construction of 2- And 4-Substituted Pyrimido[1,2- b]indazole from 3-Aminoindazoles and Ynals
Liu, Xiang,Zhou, Jinlei,Lin, Jiatong,Zhang, Zemin,Wu, Suying,He, Qiuxing,Cao, Hua
, p. 9107 - 9116 (2021/07/19)
A straightforward and novel controllable site-selective construction of 2- and 4-substituted pyrimido[1,2-b]indazole from 3-aminoindazoles and ynals has been developed. The high regioselectivity of this reaction could be easily switched by converting different catalytic systems. In this way, a series of 2- and 4-substituted pyrimido[1,2-b]indazole derivatives were obtained in moderate to good yields. In addition, the photophysical properties of compound 3a prepared by the present method were discussed.
Aerobic α,β-C(sp3)-H Bond Difunctionalization and C-N Bond Cleavage of Triethylamine: Difunctional Ammonium Iodide Enabling the Regioselective Synthesis of 4-Arylpyrimido[1,2- b]indazoles
Gao, Qinghe,Han, Xinya,Tong, Peiyuan,Zhang, Zhiang,Shen, Haotian,Guo, Yanrong,Bai, Suping
supporting information, p. 6074 - 6078 (2019/07/31)
A novel method for the regioselective synthesis of 4-arylpyrimido[1,2-b]indazoles has been developed via the dual C(sp3)-H bond functionalization and C-N bond cleavage of triethylamine. The elusive acyclic enamine intermediates are effectively in situ generated and captured by aromatic aldehydes to form a wide array of tricyclic products from 3-aminoindazoles under the NH4I-mediated aerobic oxidative conditions. This reaction features easily available feedstock, green and economic conditions, and valuable products.
