Stille Cross‐Coupling of a Racemic Planar‐Chiral Ferrocene and Crystallographic Trace Analysis of Catalysis Intermediates and By‐products |
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| Authors: | Immo Weber Frank W. Heinemann Panagiotis Bakatselos Ulrich Zenneck |
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| Affiliation: | 1. Institut für Anorganische Chemie, Friedrich‐Alexander‐Universit?t Erlangen‐Nürnberg, Egerlandstrasse 1, D‐91058 Erlangen;2. Present address: Kunststoff‐ und Metallwaren‐Fabrik (KUM) GmbH & Co. KG, Abteilung Forschung und Entwicklung, Essenbacher Strasse 2, D‐91054 Erlangen (phone: ++49‐(0)9131‐826823;3. fax: ++49‐(0)9131‐788629). |
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| Abstract: | A pressure‐controlled procedure for the SN1 reaction of rac‐1‐[(dimethylamino)methyl]‐2‐(tributylstannyl)ferrocene ( 1 ) to rac‐1‐(phthalimidomethyl)‐2‐(tributylstannyl)ferrocene ( 2 ) was developed. Pd0‐Catalyzed Stille coupling of 2 with iodobenzene afforded rac‐1‐phenyl‐2‐(N‐phthalimidomethyl)ferrocene ( 5 ) in 74% yield; after trace enrichment by crystallization of the combined mother liquors, one single crystal of each, 5 , catalysis intermediate trans‐iodo(σ‐phenyl)bis(triphenylarsino)palladium(II) ( 7 ), trans‐diiodobis(triphenylarsino)palladium(II) ( 8 ), and rac‐2,2′‐bis(phthalimidomethyl)‐1,1′‐biferrocene ( 9 ) could be isolated by crystal sorting under a microscope and characterized by X‐ray crystal structure analysis. Furthermore, 5 was deprotected to amine ( 11 ), which does even survive the Birch reduction to rac‐1‐(aminomethyl)‐2‐(cyclohexa‐2,5‐dienyl)ferrocene ( 12 ). |
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| Keywords: | Stille cross‐coupling reaction Ferrocene complexes X‐Ray crystallography Palladium complexes Catalysis |
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