Preparation of phenanthrenes from ortho-amino-biphenyls and alkynes via base-promoted homolytic aromatic substitution
作者:Marcel Hartmann、Constantin Gabriel Daniliuc、Armido Studer
DOI:10.1039/c4cc10063h
日期:——
transition-metal-free phenanthrene synthesis starting from readily accessible ortho-amino-biaryls is presented. The biarylamines are in situ transformed into the corresponding diazonium salts which upon single electron reduction give the corresponding aryl radicals. Addition to an alkyne and subsequent base promoted homolyticaromaticsubstitution (BHAS) provide phenanthrenes in moderate to good yields
Sequential Cross‐Coupling/Annulation of
<i>ortho</i>
‐Vinyl Bromobenzenes with Aromatic Bromides for the Synthesis of Polycyclic Aromatic Compounds
作者:Dong Wei、Meng‐Yao Li、Bin‐Bin Zhu、Xiao‐Di Yang、Fang Zhang、Chen‐Guo Feng、Guo‐Qiang Lin
DOI:10.1002/anie.201910792
日期:2019.11.11
A sequential cross-coupling/annulation of ortho-vinyl bromobenzenes with aromatic bromides was realized, providing a direct and modular approach to access polycyclicaromaticcompounds. A vinyl-coordinated palladacycle was proposed as the key intermediate for this sequential process. Excellent chemoselectivity and regioselectivity were observed in this transformation. The practicability of this method
Extended Study of Visible-Light-Induced Photocatalytic [4 + 2] Benzannulation: Synthesis of Polycyclic (Hetero)Aromatics
作者:Tanmay Chatterjee、Da Seul Lee、Eun Jin Cho
DOI:10.1021/acs.joc.7b00413
日期:2017.4.21
extended study of [4 + 2] benzannulation reactions of 2-(hetero)aryl-substituted anilines with alkynes by visible light photocatalysis. The method requires the use of tBuONO as a diazotizing agent and 0.3 mol % of fac-Ir(ppy)3 as a photocatalyst at room temperature. The reaction proceeded in a chemo- and regioselective manner with high functionalgroup tolerance under mild conditions allowing the preparation
Electrochemically driven [4+2] benzannulation: synthesis of polycyclic (hetero)aromatic compounds
作者:Yunlong Liu、Pengcheng Zhou、Yingli Xu、Zhiqi Yang、Dong Wang
DOI:10.1039/d2cc06552e
日期:——
A green and economical electrochemical protocol has been developed to synthesize polycyclic (hetero)aromatic compounds by the [4+2] benzannulation of biaryldiazonium salts with alkynes. This protocol features a broad substrate scope. Instead of requiring diazonium reagents, these reactions can begin from anilines and can be carried out in one pot. Moreover, the readily accessible scale-up synthesis