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Transition‐Metal‐Free Synthesis of Heterobiaryls through 1,2‐Migration of Boronate Complex
Author(s) -
Paul Swagata,
Das Kanak Kanti,
Manna Samir,
Panda Santanu
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201904761
Subject(s) - benzothiophene , benzofuran , chemistry , furan , aryl , electrophile , combinatorial chemistry , indole test , transition metal , nucleophile , thiophene , electrophilic substitution , suzuki reaction , nucleophilic aromatic substitution , organic chemistry , nucleophilic substitution , catalysis , alkyl
The synthesis of a diverse range of heterobiaryls has been achieved by a transition‐metal‐free sp 2 –sp 2 cross‐coupling strategy using lithiated heterocycle, aryl or heteroaryl boronic ester and an electrophilic halogen source. The construction of heterobiaryls was carried out through electrophilic activation of the aryl–heteroaryl boronate complex, which triggered 1,2‐migration from boron to the carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield. A comprehensive 11 B NMR study has been conducted to support the mechanism. The cross coupling between two nucleophilic cross coupling partners without transition metals reveals a reliable manifold to procure heterobiaryls in good yields. Various heterocycles like furan, thiophene, benzofuran, benzothiophene, and indole are well tolerated. Finally, we have successfully demonstrated the gram scale synthesis of the intermediates for an anticancer drug and OLED material using our methodology.