The Dewar Isomer of 1, 2‐Dihydro‐1, 2‐azaborinines: Isolation, Fragmentation, and Energy Storage. (30th March 2018)

• Record Type: Journal Article
• Authors: Edel, Klara; Yang, Xinyu; Ishibashi, Jacob S. A.; Lamm, Ashley N.; Maichle‐Mössmer, Cäcilia; Giustra, Zachary X.; Liu, Shih‐Yuan; Bettinger, Holger F.
• Is Part Of: Angewandte Chemie. Volume 130:Number 19(2018)
• Page Start: 5394
• Page End: 5398
• Publication Date: 2018-03-30
• Subjects: Bor-Stickstoff-Heterocyclen -- Elektrocyclische Reaktionen -- Nachhaltige Chemie -- Photoisomerisierungen -- Valenzisomerisierungen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201712683
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The photochemistry of 1, 2‐dihydro‐1, 2‐azaborinine derivatives was studied under matrix isolation conditions and in solution. Photoisomerization occurs exclusively to the Dewar valence isomers upon irradiation with UV light (>280 nm) with high quantum yield (46 %). Further photolysis with UV light (254 nm) results in the formation of cyclobutadiene and an iminoborane derivative. The thermal electrocyclic ring‐opening reaction of the Dewar valence isomer back to the 1, 2‐dihydro‐1‐ tert ‐butyldimethylsilyl‐2‐mesityl‐1, 2‐azaborinine has an activation barrier of (27.0±1.2) kcal mol −1 . In the presence of the Wilkinson catalyst, the ring opening occurs rapidly and exothermically (Δ H =(−48±1) kcal mol −1 ) at room temperature.