(o-Phenylenediamino)borylstannanes: Efficient Reagents for Borylation of Various Alkyl Radical Precursors

(o-Phenylenediamino)borylstannanes were newly synthesized to achieve radical boryl substitutions of a variety of alkyl radical precursors. Dehalogenative, deaminative, decharcogenative, and decarboxylative borylations proceeded in the presence of a radical initiator to give the corresponding organic boron compounds. Radical clock experiments and computational studies have provided insights into the mechanism of the homolytic substitution (S(H)2) of the borylstannanes with alkyl radical intermediates. DFT calculation disclosed that the phenylenediamino structure lowered the LUMO level including the vacant p-orbital on the boron atom to enhance the reactivity to alkyl radicals in S(H)2. Moreover, C(sp(3))-H borylation of THF was accomplished using the triplet state of xanthone.

Automated summary

(o-Phenylenediamino)borylstannanes were synthesized to achieve radical boryl substitutions of alkyl radical precursors, providing insight into the mechanism of homolytic substitution. The phenylenediamino structure was found to enhance reactivity to alkyl radicals in the reaction process. Additionally, C(sp(3))-H borylation of THF was successfully achieved using xanthone's triplet state.