Rhodium‐Catalyzed CH Annulation of Nitrones with Alkynes: A Regiospecific Route to Unsymmetrical 2,3‐Diaryl‐Substituted Indoles |
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Authors: | Hao Yan Dr. Haolong Wang Dr. Xincheng Li Dr. Xiaoyi Xin Dr. Chunxiang Wang Prof. Dr. Boshun Wan |
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Affiliation: | Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China) |
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Abstract: | The direct C? H annulation of anilines or related compounds with internal alkynes provides straightforward access to 2,3‐disubstituted indole products. However, this transformation proceeds with poor regioselectivity in the synthesis of unsymmetrically 2,3‐diaryl substituted indoles. Herein, we report the rhodium(III)‐catalyzed C? H annulation of nitrones with symmetrical diaryl alkynes as an alternative method to prepare 2,3‐diaryl‐substituted N‐unprotected indoles with two different aryl groups. One of the aryl substituents is derived from N?C‐aryl ring of the nitrone and the other from the alkyne substrate, thus providing the indole products with exclusive regioselectivity. |
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Keywords: | alkynes C H activation indoles nitrones rhodium |
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