Direkte Synthese von funktionalisierten 1,2‐Azaborininen

Abstract

Ein neuer katalytischer Zugang zu funktionalisierten 1,2-Azaborininen konnte durch [2+2]/[2+4]-Cycloadditionen von Di-tert-butyliminoboranen und Alkinen in Gegenwart eines Rhodiumkatalysators erçffnet werden. Die ersten Beispiele für Ferrocen-funktionalisierte Azaborinine konnten so synthetisiert werden. Außerdem kann die Regioselektivität dieser Reaktion über die Bildung eines intermediären Rhodium-1,2-Azaboret-Komplexes kontrolliert werden, was zu einem ersten Azaborininboronsäureester führte. Die Isolierung eines BN-Isosters mit einer NH-Gruppe wurde durch Eliminierung von Isobuten aus einer N(tBu)-Einheit unter thermolytischen Bedingungen erreicht. Quantenchemische Untersuchungen liefern weitere Einblicke in die Bildung von 1,2-Azaborininen und die Eliminierung von Isobuten aus der N(tBu)-Gruppe.

Design of Small Intramolecular Singlet Fission Chromophores: An Azaborine Candidate and General Small Size Effects

“…Our study is based on the recently proposed azaborine-substituted molecules . Azaborine chemistry is a rapidly advancing field, − and the potential application of azaborine-substituted molecules in singlet fission is starting to be realized . We hope that this study will further cross-link the two vibrant fields and lead to fruitful results in the future.…”

Photoionization and Pyrolysis of a 1,4‐Azaborinine: Retro‐Hydroboration in the Cation and Identification of Novel Organoboron Ring Systems

“…This outcome is in contrast with very recent results from Braunschweig and co-workers, in which isobutene elimination from an NtBu group of a 1,2-azaborinine was observed under thermolytic conditions, rather than from a BtBu group. [20] The isobutene elimination is presumably facilitated by steric congestion as imposed by two adjacent tBu groups in the 1,2 isomer. However, the discrepancy in which group loses the isobutene between this work and the previous system may be both related to electronic differences between the 1,2-and 1,4-azaborinine isomers and to the difference between the neutral and cationic compound.…”

Through-Linker Intramolecular Singlet Fission: General Mechanism and Designing Small Chromophores

“…The F atoms further enhance this character to have E (S 1 ) > 2 E (T 1 ) . Our purpose of choosing the 1 -unit is to cross-link SF with the vibrant field of azaborine chemistry. , The synthesis of 1 or structures based on this core has not been reported. However, the chemically persistent 2 and 2 ′ that share similar structural features with 1 have been synthesized. , This raises our confidence in the future synthesis of the designed chromophores here.…”