نبذة مختصرة : The tandem intramolecular hydroarylation of alkynes accompanied by a 1,2-aryl shift is described. Harnessing the unique electron-rich character of 1,4-dihydropyrrolo[3,2-b]pyrrole scaffold, we demonstrate that the hydroarylation of alkynes proceeds at the already occupied positions 2 and 5 leading to a 1,2-aryl shift. Remarkably, the reaction proceeds only in the presence of cationic gold catalyst, and it leads to heretofore unknown π-expanded, centrosymmetric pyrrolo[3,2-b]pyrroles. The utility is verified in the preparation of 13 products that bear six conjugated rings. The observed compatibility with various functional groups allows for increased tunability with regard to the photophysical properties as well as providing sites for further functionalization. Computational studies of the reaction mechanism revealed that the formation of the sixmembered rings accompanied with a 1,2-aryl shift is both kinetically and thermodynamically favourable over plausible formation of products containing 7-membered rings. Steady-state UV/visible spectroscopy reveals that upon photoexcitation, the prepared Sshaped N-doped nanographenes undergo mostly radiative relaxation leading to large fluorescence quantum yields. Their optical properties are rationalized through time-dependent density functional theory calculations. We anticipate that this chemistry will empower the creation of new materials with various functionalities. ; EU’s Horizon 2020 research and innovation programme under Grant Agreement No 860762 ; Polish National Science Centre (HARMONIA 2018/30/M/ST5/00460) ; Foundation for Polish Science (TEAM POIR.04.04.00-00-3CF4/16-00 and START scholarship no. 039.2017) ; scholarship awarded by the Polish Ministry of Education and Science to outstanding young scientists ; French Agence Nationale de la Recherche (ANR) for support under contract No. ANR-20-CE29-0005 (BSE-Forces) ; Wroclaw Centre for Networking and Supercomputing (grant no. 518).
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