Frustrated Lewis Pair‐Catalyzed Cycloisomerization of 1,5‐Enynes via a 5‐endo‐dig Cyclization/Protodeborylation Sequence |
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| Authors: | Sergej Tamke Dr Zheng‐Wang Qu Nikolai A Sitte Dr Ulrich Flörke Prof Dr Stefan Grimme Prof Dr Jan Paradies |
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| Institution: | 1. Institute of Organic Chemistry, University of Paderborn, Paderborn, Germany;2. Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, University of Bonn, Bonn, Germany;3. Institute of Inorganic and Analytical Chemistry, University of Paderborn, Germany |
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| Abstract: | The first frustrated Lewis pair‐catalyzed cycloisomerization of a series of 1,5‐enynes was developed. The reaction proceeds via the π‐activation of the alkyne and subsequent 5‐endo‐dig cyclization with the adjacent alkene. The presence of PPh3 was of utmost importance on the one hand to prevent side reactions (for example, 1,1‐carboboration) and on the other hand for the efficient protodeborylation to achieve the catalytic turnover. The mechanism is explained on the basis of quantum‐chemical calculations, which are in full agreement with the experimental observations. |
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| Keywords: | 1 5-enynes cycloisomerization frustrated Lewis pairs kinetic isotope effect protodeborylation |
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