%0 Generic
%A Tu, Xing-Jun
%A Hao, Wen-Juan
%A Ye, Qin
%A Wang, Shuang-Shuang
%A Jiang, Bo
%A Li, Guigen
%A Tu, Shu-Jiang
%D 2015
%T Four-Component Bicyclization
Approaches to Skeletally
Diverse Pyrazolo[3,4‑b]pyridine Derivatives
%U https://acs.figshare.com/articles/dataset/Four_Component_Bicyclization_Approaches_to_Skeletally_Diverse_Pyrazolo_3_4_i_b_i_pyridine_Derivatives/2044260
%R 10.1021/jo502096t.s002
%2 https://acs.figshare.com/ndownloader/files/3615576
%K multicyclic
%K 17 examples
%K bicyclization
%K 37 examples
%K pyrazolo
%X A novel four-component bicyclization
strategy has been established,
allowing a flexible and practical approach to 37 examples of multicyclic
pyrazolo[3,4-b]pyridines from low-cost and readily
accessible arylglyoxals, pyrazol-5-amines, aromatic amines, 4-hydroxy-6-methyl-2H-pyran-2-one, and cyclohexane-1,3-diones. The polysubstituted
cyclopenta[d]pyrazolo[3,4-b]pyridines
were stereoselectively synthesized through a microwave-assisted special
[3+2+1]/[3+2] bicyclization with good control of the spatial configuration
of exocyclic double bonds. The novel [3+2+1]/[2+2+1] bicyclization
resulted in 17 examples of unreported pyrazolo[3,4-b]pyrrolo[4,3,2-de]quinolones. Reasonable mechanisms
for forming two new types of multicyclic pyrazolo[3,4-b]pyridines are also proposed.
%I ACS Publications