For the synthesis of an ortho-dithienylpyrene, a K-region bromination of pyrene was developed which enabled the first reported, non-statistical asymmetric functionalization of pyrene at the 4, 5, 9 and 10 positions. Crystal structures, optical and electronic properties and FET characteristics have been investigated.
Regioselective Synthesis of Unsymmetric Tetra- and Pentasubstituted Pyrenes with a Strategy for Primary <i>C</i>-Alkylation at the 2-Position
作者:Ana M. Dmytrejchuk、Sydney N. Jackson、Rolande Meudom、John D. Gorden、Bradley L. Merner
DOI:10.1021/acs.joc.8b01491
日期:2018.9.7
The synthesis of 1,2,4,5- and 1,2,9,10-tetrasubstituted and 1,2,4,5,8-pentasubsutituted pyrenes has been achieved by initially functionalizing the K-region of pyrene. Bromination, acylation, and formylation reactions afford high to moderate levels of regioselectivity, which facilitate the controlled introduction of other functional groups about 4,5-dimethoxypyrene. Access to 4,5-dimethoxypyren-1-ol
10-tetrabromopyrene-4,5-dione as the key intermediate. The effects of the position and number of the ethynyl groups on the physicochemical properties of the corresponding pyrenes were clarified by comparison with 4,5,9,10-tetraethynylpyrene and 2,7-diethynylpyrene derivatives. The prepared hexaethynylpyrenes that bear benzene moieties self-assemble via π–π stacking in solution and/or the condensed phase.
Allylation of Orthoquinones Towards Annulated Polycyclic Aromatic Systems
作者:Mariusz Kędziorek、Liliana Dobrzańska
DOI:10.3390/molecules23082043
日期:——
Promising results of an efficient and convenient strategy for the annulation of polycyclic aromatic compounds (PACs), employing orthoquinones as starting material and comprising allylation, pinacol rearrangement, ring-closing metathesis (RCM), and one-pot reduction followed by Wagner-Meerwein rearrangement, are presented. The strategy involves introducing triallylborane prepared in situ in the allylation