The Dewar Isomer of 1,2‐Dihydro‐1,2‐azaborinines: Isolation,Fragmentation, and Energy Storage |
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| Authors: | Klara Edel Xinyu Yang Jacob S. A. Ishibashi Ashley N. Lamm Cäcilia Maichle‐Mössmer Zachary X. Giustra Shih‐Yuan Liu Holger F. Bettinger |
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| Affiliation: | 1. Institut für Organische Chemie, Universit?t Tübingen, Tübingen, Germany;2. Department of Chemistry, Boston College, Chestnut Hill, MA, USA;3. Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA;4. Institut für Anorganische Chemie, Universit?t Tübingen, Tübingen, Germany |
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| 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 (ΔH=(?48±1) kcal mol?1) at room temperature. |
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| Keywords: | boron– nitrogen heterocycles electrocyclic reactions photoisomerization sustainable chemistry valence isomerization |
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