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The Dewar Isomer of 1,2-Dihydro-1,2-azaborinines: Isolation, Fragmentation, and Energy Storage.

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 (?H=(-48±1)?kcal?mol-1 ) at room temperature.

SUBMITTER: Edel K

PROVIDER: S-EPMC6214188 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature

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The Dewar Isomer of 1,2-Dihydro-1,2-azaborinines: Isolation, Fragmentation, and Energy Storage.

Edel Klara K Yang Xinyu X Ishibashi Jacob S A JSA Lamm Ashley N AN Maichle-Mössmer Cäcilia C Giustra Zachary X ZX Liu Shih-Yuan SY Bettinger Holger F HF

Angewandte Chemie (International ed. in English) 20180330 19

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-butyldimethy ...[more]

PMID: 29457683

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