title: Tuned C-H functionalization to construct aza-podophyllotoxin/aza-conidendrin derivatives by means of domino cyclization.
abstract: An efficient domino cyclization method for the construction of aza-podophyllotoxin/aza-conidendrin derivatives has been established. Reactions of different dienes with aryl halides in the presence of a palladium catalytic system produced different kinds of podophyllotoxin derivatives through a highly regioselective C-H functionalization. Treatment of dienes with aryl halides that have electron-withdrawing substituents on the phenyl ring created aza-podophyllotoxin derivatives by means of the functionalization of the C-H bonds ortho to the C-halide bonds of the incoming aryl halides. The reaction of dienes with 1-iodobenzene or aryl halides that incorporate electron-donating groups produced aza-conidendrin derivatives by means of the functionalization of both sp(3) C-H and sp(2) C-H bonds. The regioselective C-H functionalization for the formation of different pseudo-podophyllotoxin/-conidendrin derivatives is proven by analyses of the (1)H NMR spectra of the products and selective X-ray analyses of the structures of the products. Thus, the palladium-catalyzed domino cyclization of 1,6-dienes for the preparation of aza-podophyllotoxin/aza-conidendrin derivatives can be controlled by selectively controlling the C-H functionalization.
authors.affiliation: Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecular-Based Materials, School of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, P.R. China. yiminhu@mail.ahnu.edu.cn
authors.forename: Yimin
authors.initials: Y
authors.lastname: Hu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Qu
authors.forename: Fenghua
authors.initials: F
authors.lastname: Wu
authors.forename: Jinghan
authors.initials: J
authors.lastname: Gui
authors.forename: Yun
authors.initials: Y
authors.lastname: Wei
authors.forename: Qiong
authors.initials: Q
authors.lastname: Hu
authors.forename: Shaowu
authors.initials: S
authors.lastname: Wang
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003500:Cyclization; D017705:Lignans / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011034:Podophyllotoxin / Q000737:chemistry*; D013764:Tetrahydronaphthalenes / Q000737:chemistry*
chemical_list: D001372:Aza Compounds; D017705:Lignans; D013764:Tetrahydronaphthalenes; C421915:conidendrin; D011034:Podophyllotoxin