Recent progress in Lewis acid-Lewis base bifunctional asymmetric catalysis

Kanai, Motomu; Kato, Norihiro; Ichikawa, Eiko; Shibasaki, Masakatsu

doi:10.1351/pac200577122047

Cited by 58 publications

(18 citation statements)

References 10 publications

(10 reference statements)

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“…[372] Shibasaki and co-workers have demonstrated that the addition of TMSCN to fluorenylimines can be effected in the presence of catalyst 330 (Table 12). [373] However, these reactions were extremely sluggish, requiring days to reach high conversion (entry 1).…”

Section: Silylcyanation Revisited: N-s* Lewis Base-lewis Acid Catalysismentioning

confidence: 99%

Lewis Base Catalysis in Organic Synthesis

2008

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The legacy of Gilbert Newton Lewis (1875-1946) pervades the lexicon of chemical bonding and reactivity. The power of his concept of donor-acceptor bonding is evident in the eponymous foundations of electron-pair acceptors (Lewis acids) and donors (Lewis bases). Lewis recognized that acids are not restricted to those substances that contain hydrogen (Brønsted acids), and helped overthrow the "modern cult of the proton". His discovery ushered in the use of Lewis acids as reagents and catalysts for organic reactions. However, in recent years, the recognition that Lewis bases can also serve in this capacity has grown enormously. Most importantly, it has become increasingly apparent that the behavior of Lewis bases as agents for promoting chemical reactions is not merely as an electronic complement of the cognate Lewis acids: in fact Lewis bases are capable of enhancing both the electrophilic and nucleophilic character of molecules to which they are bound. This diversity of behavior leads to a remarkable versatility for the catalysis of reactions by Lewis bases.

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Section: Silylcyanation Revisited: N-s* Lewis Base-lewis Acid Catalysismentioning

confidence: 99%

Lewis Base Catalysis in Organic Synthesis

2008

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“…[372] Shibasaki und Mitarbeiter berichteten Schema 112]. [378] Für die asymmetrische Cyanosilylierung von Aldehyden wurde eine Reihe sehr ähnlicher Systeme beschrieben, die sowohl Lewis-saure als auch Lewis-basische Gruppen enthalten [Gl.…”

Section: Asymmetrische Alkylierungen Mit Diethylzinkunclassified

Lewis‐Base‐Katalyse in der organischen Synthese

2008

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Das Erbe von Gilbert Newton Lewis (1875–1946) ist im Wörterbuch der chemischen Bindung und Reaktivität allgegenwärtig. Die Bedeutung seines Konzepts der Donor‐Akzeptor‐Bindung kommt in den eponymen Grundbegriffen für Elektronenpaarakzeptoren (Lewis‐Säuren) und ‐donoren (Lewis‐Basen) zum Ausdruck. Lewis erkannte, dass Säuren nicht automatisch Wasserstoff enthalten müssen (Brønsted‐Säuren) und trug so zum Sturz des “modernen Protonenkults” bei. Seine Entdeckung läutete zunächst die Entwicklung von Lewis‐Säuren als Reagentien und Katalysatoren für organische Reaktionen ein, in den letzten Jahren wurde aber offensichtlich, dass für diese Zwecke auch Lewis‐Basen eingesetzt werden können. Bezüglich der Beschleunigung chemischer Reaktionen ergänzen Lewis‐Basen die entsprechenden Lewis‐Säuren nicht nur elektronisch: Tatsächlich können Lewis‐Basen die Elektrophilie wie auch die Nucleophilie der Verbindungen verstärken, an die sie gebunden werden. Diese unterschiedliche Reaktivität resultiert in einer bemerkenswerten Vielfalt Lewis‐Base‐katalysierter Reaktionen.

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“…In general, two types of activation modes exist for catalytic nucleophilic addition reactions: (1) activation of nucleophile precursors by basic catalysts to abstract their acidic portions, such as α-hydrogen atoms, and (2) lowering the LUMO levels of electrophiles by interaction with Brønsted or Lewis acidic catalysts. Thus, the ideal pathway for nucleophilic reactions is dual activation of both electrophiles and nucleophiles by acidic and basic catalysts, respectively (Scheme 1) 1), 2) . However, the existence of both strongly acidic and basic species in solution induces neutralization resulting in inactive salts.…”

Section: Introductionmentioning

confidence: 99%

“…Later reports described, several bifunctional catalysts with both an organic acid and base used for carbon _ carbon bond-forming reactions 8) 11) . For type (2) catalysts, the silanol group on the silica surface was reported as a weak acid site for the promotion of amineor NH2 group-catalyzed reactions 12), 13) . In 2003, Kubota and co-workers reported that silanol groups on SiO2 significantly enhanced amine-catalyzed aldol reactions 14) .…”

Section: Introductionmentioning

confidence: 99%

Synergistic Catalysis by Multifunctionalized Solid Surfaces for Nucleophilic Addition Reactions

Motokura

2014

J. Jpn. Petrol. Inst.

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This review paper treats with acid-base and Pd-complex-base bifunctional catalyst surfaces used to catalyze nucleophilic addition reactions. A silica _ alumina-supported tertiary amine was found to be a highly active hetero geneous catalyst for Michael additions and cyano-ethoxycarbonylation. These reactions barely proceeded with either a homogeneous amine or silica _ alumina support, indicating that synergistic catalysis occurred between the silica _ alumina surface and basic amine. Silica _ alumina, which contains both tertiary and primary amines, was an efficient catalyst for one-pot synthesis of 1,3-dinitroalkanes from aldehydes and nitromethane. The acidbase synergistic catalysis was applied to metal complex-base synergistic catalysis. Both the Pd-complex and tertiary amine-immobilized silica was an excellent heterogeneous catalyst for the Tsuji-Trost reaction. Spectroscopic analyses, such as solid-state MAS NMR, revealed the structures of prepared catalysts, immobilization mechanism of amine groups on the silica _ alumina surface, and reaction intermediates and catalytic reaction mechanism. Substrate scope for the cyanation, Michael reaction, 1,3-dinitroalkane synthesis, and the Tsuji-Trost reaction are also described.

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Recent progress in Lewis acid-Lewis base bifunctional asymmetric catalysis

Abstract: Two enantioselective cyanation reactions, the Strecker reaction of ketoimines and the Reissert reaction of pyridine derivatives, promoted by Lewis acid-Lewis base bifunctional asymmetric catalysts are described.

Cited by 58 publications

References 10 publications

Lewis Base Catalysis in Organic Synthesis

Lewis Base Catalysis in Organic Synthesis

Lewis‐Base‐Katalyse in der organischen Synthese

Synergistic Catalysis by Multifunctionalized Solid Surfaces for Nucleophilic Addition Reactions

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