meso ‐Functionalization of Boron(III) Subporphyrin with Boron(III) meso ‐Lithiosubporphyrin

Boron(III) meso ‐lithiosubporphyrin was prepared by bromine–lithium exchange of B‐tolyl B III meso ‐bromosubporphyrin with n ‐butyllithium at −98 °C. The resulting subporphyrinyllithium was treated with various electrophiles such as benzophenone, N , N ‐dimethylformamide, CO 2 , chlorotrimethylsilane, N ‐fluorobenzenesulfonimide, and dimesitylboryl fluoride to give the corresponding meso ‐functionalized B III subporphyrins. The nucleophile was also used to construct B III subporphyrin dimers such as bis(B III subporphyrinyl)ketone, bis(B III subporphyrinyl)carbinol, and disilane‐bridged B III subporphyrin dimer. The structural, optical, and electrochemical properties of these meso ‐functionalized B III subporphyrins were examined by UV/Vis absorption and fluorescence spectroscopy, electrochemical studies, and DFT calculations.