Combination of sp2‐ and sp3‐Type Phosphorus Atoms for Gold Chemistry: Preparation,Structure, and Catalytic Activity of Gold Complexes That Bear Ligated 2‐Silyl‐1,3‐diphosphapropenes |
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Authors: | Prof. Dr. Shigekazu Ito Lili Zhai Prof. Dr. Koichi Mikami |
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Affiliation: | Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2‐12‐1 Ookayama, Meguro, Tokyo 152‐8552 (Japan), Fax: (+81)?3‐5734‐2143 |
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Abstract: | Kinetically protected 2‐silyl‐1,3‐diphosphapropenes that bear both sp2‐ and sp3‐type phosphorus atoms were employed in the preparation of gold complexes. The structural properties of the 1,3‐diphosphapropene digold(I) complexes were characterized by spectroscopic and crystallographic analyses, which revealed unique aurophilic interactions and conformational properties of the ligand. The 2‐silyl‐1,3‐diphosphapropene‐bis(chlorogold) complexes catalyzed cycloisomerization reactions of 1,6‐enyne derivatives even in the absence of silver co‐catalyst, and were able to be recovered after the reaction. The catalytic activity of the digold complexes primarily depended on the sp2‐type phosphorus atom and the silyl group, and could be tuned by the sp3‐phosphino group. Additionally, results on the catalytic activity of the digold complex in the presence and absence of silver salts showed considerable differences. |
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Keywords: | aurophilicity cycloisomerization enynes gold phosphaalkenes |
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