Abstract
A versatile synthetic route to distannyl-substituted polyarenes was developed via double radical peri-annulations. The cyclization precursors were equipped with propargylic OMe traceless directing groups (TDGs) for regioselective Sn-radical attack at the triple bonds. The two peri-annulations converge at a variety of polycyclic cores to yield expanded difunctionalized polycyclic aromatic hydrocarbons (PAHs). This approach can be extended to triple peri-annulations, where annulations are coupled with a radical cascade that connects two preexisting aromatic cores via a formal C-H activation step. The installed Bu3Sn groups serve as chemical handles for further functionalization via direct cross-coupling, iodination, or protodestannylation and increase solubility of the products in organic solvents. Photophysical studies reveal that the Bu3Sn-substituted PAHs are moderately fluorescent, and their protodestannylation results in an up to 10-fold fluorescence quantum yield enhancement. DFT calculations identified the most likely possible mechanism of this complex chemical transformation involving two independent peri-cyclizations at the central core.
Original language | English |
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Pages (from-to) | 8352-8366 |
Number of pages | 15 |
Journal | Journal of the American Chemical Society |
Volume | 142 |
Issue number | 18 |
DOIs | |
State | Published - May 6 2020 |
Externally published | Yes |
Funding
E.G.-R. is thankful for the support provided by CONACYT throughout his graduate studies. Financial support of this work by the National Science Foundation is gratefully acknowledged (CHE-1800329). Computational resources were provided by NSF XSEDE (TG-CHE160006) and FSU Research Computing Center. G.P.G. thanks Professor Alan Aspuru-Guzik (University of Toronto) for the support. E.G.-R. is thankful for the support provided by CONACYT throughout his graduate studies. Financial support of this work by the National Science Foundation is gratefully acknowledged (CHE-1800329). Computational resources were provided by NSF XSEDE (TG-CHE160006) and FSU Research Computing Center. G.P.G. thanks Professor Alán Aspuru-Guzik (University of Toronto) for the support.