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New Catalysts for Base-Catalysed Hydroamination Reactions of Olefins

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New Catalysts for Base-Catalysed Hydroamination Reactions of Olefins Den Naturwissenschaftlichen Fakultäten der Friedrich-Alexander-Universität Erlangen-Nürnberg zur Erlangung des Doktorgrades vorgelegt von Patricia Horrillo Martínez aus Tudela de Navarra, Spanien Als Dissertation genehmigt von den Naturwissenschaftlichen Fakultäten der Universität Erlangen-Nürnberg Tag der mündlichen Prüfung: 18.07.2008 Vorsitzender der Promotionskommission: Prof. Dr. E. Bänsch Erstberichterstatter: Assist. Prof. Dr. K. C. Hultzsch Zweitberichterstatter: Prof. Dr. H. Gröger a mis Padres y Achim Die vorliegende Arbeit wurde am Institut für Organische Chemie der Friedrich-Alexander- Universität Erlangen-Nürnberg in der Zeit von Oktober 2003 bis September 2007 unter Anleitung von Priv. Doz. Dr. Kai C. Hultzsch angefertigt. Ich danke Dr. Kai C. Hultzsch für den wissenschaftlichen Anstoß, das stetige Interesse an dieser Arbeit sowie die wertvolle Hilfe bei der Erstellung dieses Manuskripts. Auch danke ich Prof. John A. Gladysz für die Möglichkeit in seiner Gruppe promovieren zu können und für die interessante Diskussionen. Den Angestellten des Organischen Instituts möchte ich für Ihre Hilfe danken: Dr. Frank Hampel und Wolfgang Donaubauer (Röntgenstrukturanalyse), Wilfried Schätzke, Christian Placht und besonderes Prof. Walter Bauer (NMR –Spektroskopie), Wolfgang Donaubauer und Margarete Dziallach (mindestens tausend mal haben Sie Massenspektren für mich gemessen), Eva Hergenröder (Elementaranalyse), Hannelore Oschmann und Robert Panzer (Chemikalien), Stefan Fronius und Bahram Saberi (Glasbläserei), Erwin Schreier und Eberhard Ruprecht (Mechanische Werkstatt), Reinhard Wolff und Holger Wohlfahrt (ehemaliger und neuer Hausmeister). Mein besonderer Dank geht auch an Dr. Frank Hampel, Christiane Brandl-Rittel und Pamela Engerer für die freundliche Hilfe mit administrativen Dingen. Ich danke meinen Laborkollegen Inka, Boyan, Alexander und vor allem Denis für die nette Atmosphäre und die gute Zusammenarbeit. Dem gesamten Arbeitskreis Gladysz (ehemalige und gegenwärtige Mitarbeiter) danke ich für die wunderbaren Jahre in Erlangen. Ihr werdet für immer in meinem Herzen bleiben. Ich danke auch den Fußballspielern des Instituts: Der Dienstag war immer etwas Besonderes. Mein herzlicher Dank gilt meinen Freunden in Deutschland (Patri 1, Verona, Laura, Elena, Yolanda, Sergio, Saul, Jose P., Ana, Carolina, Anne-So, Patrick) und in Spanien (Eva und Pere, Sonia, Chloe, Roser und Joan, Salut, Maria, Isabel, Anna, Adrià, Jose A.) für die moralische Unterstützung. Ganz besonders danke ich meinen Eltern, meiner Schwester und Achim für ihre bedingungslose Unterstützung. Zusammenfassung Die vorliegende Arbeit umfasst die Synthese von neuartigen, Prolin-modifizierten, chiralen Binaphthyl-Komplexen ausgewählter Hauptgruppen- (Li, Mg, Zn) und Seltenerdmetallen (Y, La), sowie deren Anwendung in der intramolekularen Hydroaminierung von Aminoalkenen, Aminodialkenen und Aminoalkinen. Hydroaminierungen von Vinylaromaten mit primären und sekundären Aminen wurden unter Verwendung geringer Katalysatorbeladungen von [(TMEDA) Li{N(SiMe3)2}] (29) bis hinab zu 2 mol% untersucht. Bei 120 °C laufen diese Reaktionen, ohne Zusatz von Lösungsmitteln, zügig und selektiv zu den anti-Markovnikov Produkten ab und ermöglichen deren Isolierung in 23-96% Ausbeute. Im Falle elektronenarmer p-Chlorstyrole oder sekundärer, zyklischer Amine, wie zum Beispiel Pyrrolidin, Piperidin oder Morpholin, kann bereits bei 25 °C langsame Hydroaminierungsaktivität festgestellt werden. Primäre Amine jedoch können einer nachfolgenden, zweiten Hydroaminierung unterliegen und somit auch zu tertiären Aminen führen. Unter Verwendung eines Amin- Überschusses war es hierbei möglich die Selektivität bezüglich des mono-hydroaminierten Produkts gegenüber dem tertiären Amin zu erhöhen. Des Weiteren wurde die intermolekulare Hydroaminierung von Vinylaromaten mit zahlreichen primären und sekundären Aminen in Anwesenheit einfacher Lithium- und Kaliumamide untersucht. Im Vergleich zu [Li{N(SiMe3)2}], konnte für [K{N(SiMe3)2}] eine höhere katalytische Aktivität bei verringerter Selektivität festgestellt werden, die sich in der Bildung unerwünschter Nebenprodukte durch α-C-H-Aktivierung äußerte. 2mol%[Li{N(SiMe3)2}] 2mol%Additiv R' Ar N Ar + HN R'R'' Ar R'' + N 25-120 °C Ar R'' R' = H Die durchgeführten Studien zur Reaktionskinetik, sowie deren theoretische Berechnung stehen im Einklang mit dem postulierten basen-katalysierten Reaktionsmechanismus. Die Reaktion primärer Amine durchläuft zwei aufeinander folgende Additions-schritte, wobei der erste signifikant schneller ablaufen muss. Der anfängliche Hydroaminierungsschritt verläuft kinetisch nach erster Ordnung bezüglich der Konzentration von Styrol und Benzylamin, jedoch nach unerwarteter nullter Ordnung bezüglich der Katalysatorkonzentration. Vorläufige Versuche deuten an, dass [(TMEDA)Li(NHCH2Ph)] eine deutlich höhere katalytische Aktivität aufweist, wodurch eine Reaktionsführung bei Raumtemperatur ermöglich wird. Die Reaktion verläuft in diesem System nach einer Kinetik erster Ordnung in Bezug auf die Konzentration an Styrol, Benzylamin und Katalysator. Die ermittelte Kinetik erster Ordnung bezüglich der Katalysatorkonzentration unterstützt den angenommenen Katalysezyklus der Lithium- Benzylamid-katalysierten Umsetzung. Die L-Prolin modifizierten, axial-chiralen Tetramin-Verbindungen (S,S,S)-DABN(MeProlin)2 ((S,S,S)-40) und (R,S,S)-DABN(MeProlin)2 ((R,S,S)-41) konnten in moderaten bis guten Ausbeuten (44-88%) hergestellt werden. Nachfolgende Lithiierung in Hexan führt zu den diastereomeren Di-Lithium Salzen [Li2{(S,S,S)-DABN (MeProline)2}]2 ((S,S,S)-47) und [Li2{(R,S,S)-DABN(MeProline)2}] ((R,S,S)-49), wobei ersteres auch durch Röntgenstrukturanalyse nachgewiesen werden konnte. Durch Modifikation des Ligandgerüstes sind auch die Komplexverbindungen [Li2{(R)-DABN (SitBuMe2)2}(THF)2] ((R)-50), Lithium (S)-1-Methyl-2-[N-1-naphthylamino)methyl]- pyrrolidin ((S)-51) und Di-lithium-(N,N-DiMeProlin)-2,2’-diamino-4,4’-di-tert-butyl- biphenyl ((S,S)-52) in 70%, 86% beziehungsweise 57% Ausbeute zugänglich. Eine Variation des Zentralmetalls führt zur Isolierung der bimetallischen Magnesium und Zink Komplexe [Mg2{(S,S,S)-DABN(MeProlin)2}{Bu}2] ((S,S,S)-53), [Mg2{(R,S,S)-DABN (MeProlin)2}{Bu}2] ((R,S,S)-54), [Zn2{(S,S,S)-DABN(MeProlin)2}{Et}2] ((S,S,S)-55) und [Zn2{(R,S,S)-DABN(MeProlin)2}{Et}2] ((R,S,S)-56) in 62-76% Ausbeute. N N Me Me NH NH NH Me NH Me N N (S,S,S)-40 (R,S,S)-41 Mit dem Lithium-Komplex (S,S,S)-47 wurde das erste Beispiel eines Lithium- Katalysators für die asymmetrische Hydroaminierung/Zyklisierung von Aminoalkenen gefunden. Für einige Aminoalkene zeigt dieser Katalysator vergleichbare Aktivitäten mit jenen, die für die Lanthanoid-basierten Systeme und die Katalysatoren mit Übergangsmetallen der vierten Gruppe gefunden wurden, wobei die Lithium-basierte viii Verbindung Enantioselektivitäten von bis zu 85% ee in der Zyklisierung von C-(1-Allyl- cyclohexyl)-methylamin (S4) erzielen konnte. Eine niedrigere Reaktivität und Selektivität der Katalysatoren (R)-50, (S)-51 und (S,S)-52 weist darauf hin, dass sowohl die chirale Diaminobinaphthyleinheit, als auch die L-Prolin-Gruppen entscheidenden Einfluss auf die Leistungsfähigkeit des Katalysators ausüben. H N 4mol%(S,S,S)-47 NH2 toluol-d8, 9h,0°C S4 P4 91% (84% ee) Weiterhin erwiesen sich die Magnesium und Zink Komplexe (S,S,S)-53, (R,S,S)-54, (S,S,S)-55, und (R,S,S)-56 als aktive Katalysatoren in der intramolekularen Hydroaminierung/Zyklisierung. Im Speziellen zeigte der Magnesium Komplex (S,S,S)-53 eine ausgesprochen hohe katalytische Aktivität für die Zyklisierungsreaktion von 2,2-Diphenyl-1-aminopent-4-en (S3), wobei im Allgemeinen niedrige Enantioselektivitäten (0-29% ee) beobachtet wurden. Kinetische Untersuchungen zur (S,S,S)-47-katalysierten Hydroaminierung/ Zyklisierung von S4 legten eine Abhängigkeit nach erster Ordnung bezüglich der Substrat- und Katalysatorkonzentration offen. Die Aktivierungsparameter für den tief- und hochliegenden Übergangszustand zu den Pyrrolidin-Produkten (S)-P4 und (R)-P4 wurde ermittelt (ΔH(S)≠ = 54(4) kJ mol-1, ΔS(S)≠ = -129(14) J K-1 mol-1 und ΔH(R)≠ = 65(5) kJ mol-1, ΔS(S)≠ = -109(17) J K-1 mol-1). Mit β-substituierten Aminoalkenen konnte die kinetische Racematspaltung unter Verwendung von (S,S,S)-47 durchgeführt werden, was im Falle der α-substituierten Analoga nur in sterisch stark abgeschirmten Systemen gelang. Die Lanthanoid Komplexe [Ln{(S,S,S)-DABN(MeProlin)2}{N(SiMe3)2}] [Ln = Y ((S,S,S)-79), La ((S,S,S)-80)] wurden in situ im NMR-Maßstab hergestellt und im Hinblick auf ihre katalytische Aktivität in Hydroaminierungs/Zyklisierungs-Reaktionen untersucht. Weiterhin wurden die kationischen Zirconium Komplexe (S,S,S)-81 und (R,S,S)-82, welche sich von den entsprechenden L-Prolin derivatisierten Diaminobinaphthyl-Liganden ableiten, in 85% beziehungsweise 99% Ausbeute synthetisiert. Die neutralen Komplexe der vierten Gruppe [M{(R)-DABN(py)2}(NMe2)2] ix (M = Ti ((R)-83), Zr ((R)-85)) konnten erhalten und NMR-spektroskopisch charakterisiert werden. Die Lanthanoid Komplexe (S,S,S)-79 und (S,S,S)-80 erwiesen sich als aktive Katalysatoren für eine Ringschlussreaktion des 2,2-Dimethyl-pent-4-enylamins (S1), wobei jedoch geringe Selektivitäten in Kauf genommen werden müssen (maximal 11% ee). Beide Katalysatoren ermöglichen auch die Umsetzung anderer Substrate zu den analogen Produkten. Um hohe Umsatzraten zu beobachten, werden hierfür allerdings lange Reaktionszeiten und in einigen
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    Gold(I)-Catalyzed Enantioselective Hydroamination of Unactivated Alkenes by Seong Du Lee Department of Chemistry Duke University Date:_______________________ Approved: ___________________________ Ross A. Widenhoefer, Supervisor ___________________________ Jiyong Hong ___________________________ Katherine J. Franz ___________________________ Qiu Wang Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry in the Graduate School of Duke University 2012 i v ABSTRACT Gold(I)-Catalyzed Enantioselective Hydroamination of Unactivated Alkenes by Seong Du Lee Department of Chemistry Duke University Date:_______________________ Approved: ___________________________ Ross A. Widenhoefer, Supervisor ___________________________ Jiyong Hong ___________________________ Katherine J. Franz ___________________________ Qiu Wang An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry in the Graduate School of Duke University 2012 i v Copyright by Seong Du Lee 2012 Abstract Numerous methodologies for efficient formation of carbon-nitrogen bonds have been developed over the decades due to the widespread importance of nitrogen containing compounds in pharmaceuticals and bulk commercial chemicals. Among many methods, hydroamination, in particular, has attracted considerable attention owing to its high atom economy and use of simple C-C substrates. As a result, numerous methods for hydroamination have been reported which employ a range of metal catalysts. However, the hydroamination of unactivated alkenes remains an unsolved challenge owing to the low reactivity of the C=C double bond. The recent development of gold(I) as an effective π-activation catalyst prompted us to develop efficient gold (I)-catalyzed methods for enatioselective intra- and intermolecular hydroamination of unactivated alkenes.
  • Catalytic Intermolecular Hydroamination of Vinyl Ethers Hydroaminationnirmal of Vinyl Ethers K

    Catalytic Intermolecular Hydroamination of Vinyl Ethers Hydroaminationnirmal of Vinyl Ethers K

    LETTER 3135 Catalytic Intermolecular Hydroamination of Vinyl Ethers HydroaminationNirmal of Vinyl Ethers K. Pahadi,* Jon A. Tunge* Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045-7582, USA Fax +1(785)8645396; E-mail: [email protected] Received 30 July 2009 the concentration of vinyl ether to 1.6 M (4 equiv) slightly Abstract: This manuscript details the development of a palladium- catalyzed hydroamination of vinyl ethers. It is proposed that palla- lowers the yield (entry 5), while using just 2 equivalents dium catalyzes the hydroamination via Brønsted base catalysis, considerably lowered the yield of aminol (entry 6) and in- where palladium is protonated by the relatively acidic sulfonamide creased the time necessary for reaction completion. More- to generate a palladium hydride as well as the active anionic sul- over, substantial quantities of enamine 4a were formed. fonamide nucleophile. Thus, this process is distinct from known Further lowering the concentration of 2 to 0.5 M dramati- palladium-catalyzed hydroaminations of styrene derivatives that cally decreased the yield of 3, and only a trace amount of utilize less acidic amines. enamine 4 was observed. Dioxane, MeCN, DCE, and Key words: hydroamination, vinyl ether, palladium, sulfonamide THF were also tested as potential solvents; only dioxane provided any product. However, when 1,4-dioxane was used as solvent, a 1:1 mixture of 3a and 4a was obtained Transition-metal-catalyzed intermolecular hydroamina- Table 1 a tion of alkenes has attracted a great attention in recent Conditions for Hydroamination years.1 Much research in this line has centered on the in- PG OBu tramolecular hydroamination of simple alkyl-substituted N 2,3 Ph a-olefins.
  • Lanthanide Chalcogenolate Complexes: Syntheses, Structures

    Lanthanide Chalcogenolate Complexes: Syntheses, Structures

    中国科技论文在线 http://www.paper.edu.cn Coordination Chemistry Reviews 250 (2006) 2059–2092 Review Lanthanide chalcogenolate complexes: Syntheses, structures and applications in organic chemistry Hong-Xi Li a, Yan-Jun Zhu a, Mei-Ling Cheng a, Zhi-Gang Ren a, Jian-Ping Lang a,b,∗, Qi Shen a a Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Engineering, Suzhou University, Suzhou 215123, Jiangsu, PR China b State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, Jiangsu, PR China Received 18 October 2005; accepted 9 February 2006 Available online 23 February 2006 Contents 1. Introduction ........................................................................................................... 2060 2. Methods of preparation ................................................................................................. 2060 2.1. Protonolysis reaction ............................................................................................. 2060 2.2. Salt metathesis reaction........................................................................................... 2062 2.3. Oxidation–reduction reaction ..................................................................................... 2063 2.3.1. Oxidation reaction of divalent lanthanocene complexes ...................................................... 2063 2.3.2. Reaction of elemental lanthanide and REER ................................................................ 2065 2.3.3. Reaction of Ln/M amalgam with REER and trans-metallation