The Synthesis of Benzimidazoles and Quinoxalines from Aromatic Diamines and Alcohols by Iridium‐Catalyzed Acceptorless Dehydrogenative Alkylation |
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Authors: | Toni Hille Dr Torsten Irrgang Prof Dr Rhett Kempe |
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Institution: | Lehrstuhl für Anorganische Chemie II, Universit?t Bayreuth, Universit?tsstrasse 30, NW I, 95440 Bayreuth (Germany), Fax: (+49)?921552157 |
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Abstract: | Benzimidazoles and quinoxalines are important N‐heteroaromatics with many applications in pharmaceutical and chemical industry. Here, the synthesis of both classes of compounds starting from aromatic diamines and alcohols (benzimidazoles) or diols (quinoxalines) is reported. The reactions proceed through acceptorless dehydrogenative condensation steps. Water and two equivalents of hydrogen are liberated in the course of the reactions. An Ir complex stabilized by the tridentate P^N^P ligand N2,N6‐bis(di‐isopropylphosphino)pyridine‐2,6‐diamine revealed the highest catalytic activity for both reactions. |
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Keywords: | acceptorless dehydrogenation alcohols benzimidazoles iridium quinoxalines |
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