One-Pot Zn/CuI/TFA-Catalyzed Domino Three-Component–Carbocyclization Reaction Involving Biphenyl-2-carbaldehydes/Alkynes/Piperidine: Allenes-Mediated Construction of Phenanthrenes
作者:Mohammad Saifuddin、Piyush K. Agarwal、Bijoy Kundu
DOI:10.1021/jo201942r
日期:2011.12.16
A one-pot protocol involving Zn/CuI/TFA-catalyzed domino three-component and subsequent carbocyclization reactions is described. The reaction proceeds via formation of propargyl amines from biphenyl-2-carbaldehydes/terminal alkynes/piperidine followed by the elimination of piperidine and ring closure to furnish phenanthrene derivatives in good yields. The strategy involves C(sp)-H activation-CH functionalization with imine-alkyne activation-1,5 hydride shift-beta-elimination of piperidine-allene formation-6 pi cycloaddition isomerization domino sequence. Evidence for the involvement of allenes as an intermediate during carbocyclization is discussed.
Synthesis of Phenanthrenes through Copper-Catalyzed Cross-Coupling of <i>N</i>-Tosylhydrazones with Terminal Alkynes
作者:Mohammad Lokman Hossain、Fei Ye、Zhenxing Liu、Ying Xia、Yi Shi、Lei Zhou、Yan Zhang、Jianbo Wang
DOI:10.1021/jo501489c
日期:2014.9.19
for the synthesis of phenanthrenes through the copper-catalyzed reaction of aromatic tosylhydrazones with terminalalkynes is explored. The reaction proceeds via the formation of an allene intermediate and subsequent six-π-electron cyclization–isomerization, affording phenanthrene derivatives in good yields. The transformation can be performed in two ways: (1) with N-tosylhydrazones derived from [1,1