Direct Synthetic Route to Functionalized 1,2‐Azaborinines |
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| Authors: | Prof?Dr Holger Braunschweig Dr K Geetharani Dr J Oscar C Jimenez‐Halla Marius Schäfer |
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| Affiliation: | Institut für Anorganische Chemie, Julius‐Maximilians‐Universit?t Würzburg, Am Hubland, 97074 Würzburg (Germany) http://www‐anorganik.chemie.uni‐wuerzburg.de/Braunschweig/index.html |
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| Abstract: | A new catalytic synthetic route to functionalized 1,2‐azaborinines has been developed by the 2+2]/2+4] cycloaddition reactions of di‐tert‐butyliminoboranes and alkynes in presence of a rhodium catalyst. The first examples of ferrocene‐functionalized azaborinines have been synthesized using this strategy. Moreover, the regioselectivity of this reaction can be controlled by the formation of an intermediate rhodium 1,2‐azaborete complex, which results in the isolation of the first azaborinine boronic ester. The isolation of an NH‐containing BN isostere by elimination of isobutene from an N(tBu) group under thermolytic conditions has also been achieved. Theoretical studies give further insight into the formation of 1,2‐azaborinines and the elimination of isobutene from the N(tBu) group. |
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| Keywords: | boron cyclization heterocycles isosterism rhodium |
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