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Desymmetrization of Dicationic Diboranes by Isomerization Catalyzed by a Nucleophile
Author(s) -
Schön Florian,
Greb Lutz,
Kaifer Elisabeth,
Himmel HansJörg
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202001640
Subject(s) - isomerization , chemistry , nucleophile , cationic polymerization , desymmetrization , catalysis , intramolecular force , boron , medicinal chemistry , photochemistry , stereochemistry , polymer chemistry , organic chemistry , enantioselective synthesis
Cationic monoboranes exhibit a rich chemistry. By constrast, only a few cationic diboranes are known, that all are symmetrically substituted. In this work, the first unsymmetrically substituted dicationic diboranes, featuring sp 2 –sp 2 ‐hybridized boron atoms, are reported. The compounds are formed by intramolecular rearrangement from preceding isomeric symmetrically substituted dicationic diboranes, a process that is catalyzed by nucleophiles. From the temperature‐dependence of the isomerization rate, activation parameters for this unprecedented rearrangement are derived. The difference in fluoride ion affinity between the two boron atoms and the bonding situation in these unique unsymmetrical dicationic diboranes are evaluated.