Zhang, Dan-Jie Xie, Ming-Sheng Qu, Gui-Rong Gao, Yao-Wei Guo, Hai-Ming Synthesis of Azacyclic Nucleoside Analogues via Asymmetric [3 + 2] Cycloaddition of 9‑(2-Tosylvinyl)‑9<i>H</i>‑purines With 9-(2-tosylvinyl)-9<i>H</i>-purines as the dipolarophiles, a series of chiral azacyclic nucleosides with four continuous stereocenters were obtained in 86–99% yields, >20:1 dr, and 94 → 99% ee via the Cu­(I)-catalyzed asymmetric [3 + 2] cycloaddition. Both (<i>E</i>)- and (<i>Z</i>)-9-(2-tosylvinyl)-9<i>H</i>-purines were suitable dipolarophiles, enriching the structure diversity of azacyclic nucleosides. Furthermore, when α-methyl imino ester was explored, the corresponding azacyclic nucleoside with a chiral quaternary stereocenter could also be afforded with excellent results. Azacyclic Nucleoside Analogues;chiral quaternary stereocenter;structure diversity;dipolarophile;azacyclic nucleoside;chiral azacyclic nucleosides;azacyclic nucleosides 2016-02-04
    https://acs.figshare.com/articles/journal_contribution/Synthesis_of_Azacyclic_Nucleoside_Analogues_via_Asymmetric_3_2_Cycloaddition_of_9_2_Tosylvinyl_9_i_H_i_purines/2072164
10.1021/acs.orglett.6b00108.s001