Iridium‐Catalyzed CH Activation versus Directed <i>ortho</i> Metalation: Complementary Borylation of Aromatics and Heteroaromatics

Hurst, Timothy E.; Macklin, Todd K.; Becker, Maike; Hartmann, Eduard; Kügel, Wolfgang; Salle, J; Batsanov, Andrei S.; Marder, Todd B.; Snieckus, Victor

doi:10.1002/chem.201000401

Cited by 111 publications

(57 citation statements)

References 60 publications

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“…8 There are several examples of catalytic ortho functionalizations of aniline. Most require the installation of a directing group prior to C–H functionalization.…”

Section: Introductionmentioning

confidence: 99%

Achieving High Ortho Selectivity in Aniline C–H Borylations by Modifying Boron Substituents

et al. 2018

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High ortho selectivity for Ir-catalyzed C–H borylations (CHBs) of anilines results when B2eg2 (eg = ethylene glycolate) is used as the borylating reagent in lieu of B2pin2, which is known to give isomeric mixtures with anilines lacking a blocking group at the 4-position. With this modification, high selectivities and good yields are now possible for various anilines, including those with groups at the 2- and 3-positions. Experiments indicate that ArylN(H)Beg species are generated prior to CHB and support the improved ortho selectivity relative to B2pin2 reactions arising from smaller Beg ligands on the Ir catalyst. The lowest-energy transition states (TSs) from density functional theory computational analyses have N–H···O hydrogen-bonding interactions between PhN(H)Beg and O atoms in Beg ligands. Ir-catalyzed CHB of PhN(H)Me with B2eg2 is also highly ortho-selective. 1H NMR experiments show that N-borylation fully generates PhN(Me)Beg prior to CHB. The TS with the lowest Gibbs energy was the ortho TS, in which the Beg unit is oriented anti to the bipyridine ligand.

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“…8 There are several examples of catalytic ortho functionalizations of aniline. Most require the installation of a directing group prior to C–H functionalization.…”

Section: Introductionmentioning

confidence: 99%

Achieving High Ortho Selectivity in Aniline C–H Borylations by Modifying Boron Substituents

et al. 2018

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“…31 Much like the sterically-controlled meta -borylation reported by Hartwig and Ishiyama, 18,22,27 the site-selectivity is determined by the steric factors. Ir complexes were uniquely active, while Mn, Re, Ru, and Rh showed no catalytic activity.…”

Section: C3–h-functionalizationmentioning

confidence: 93%

“…27 The amide groups in these substrates were found to provide steric shielding for the C–H bonds in the adjacent positions under the conditions of the Ir-catalyzed borylation. Thus, regioselectivity of this method is complimentary to that of the directed ortho metalation (DoM).…”

Section: C3–h-functionalizationmentioning

confidence: 99%

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Recent advances in the C–H-functionalization of the distal positions in pyridines and quinolines

2015

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This review summarizes recent developments in the C–H-functionalization of the distal positions of pyridines, quinolines and related azaheterocycles. While the functionalization of the C2 position has been known for a long time and is facilitated by the proximity to N1, regioselective reactions in the distal positions are more difficult to achieve and have only emerged in the last decade. Recent advances in the transition metal-catalyzed distal C–H-functionalization of these synthetically-important azaheterocycles are discussed in detail, with the focus on the scope, site-selectivity and mechanistic aspects of the reactions.

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“…[66] In diesem Fall ist die bevorzugte Koordination des Rhodiumkomplexes an die benzylische Position (39) 19 b). [68] Ein weiteres probates Mittel zur Kontrolle der Selektivität bei Hydroformylierungen ist der Gebrauch von Gerüstliganden, die kovalent und reversibel an das Substrat binden, was zu einer temporär intramolekularen Reaktion führt (Schema 20).…”

Section: Regioselektive Funktionalisierung Von Alkenenunclassified

Katalytische selektive Synthese

2012

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Der Verlauf und das Produkt einer Reaktion lassen sich gezielt über die Katalysatorstruktur steuern, selbst bei nahezu identischen Reaktionsbedingungen. Katalysatorkontrollierte Selektivität ist in der enantioselektiven Synthese gut etabliert, in katalytischen regio‐, chemo‐ und produktselektiven Reaktionen aber wenig verbreitet. Dieser Aufsatz beschreibt, wie eine Ausgangsverbindung lediglich durch die Auswahl des Katalysators selektiv in zwei oder mehr unterschiedliche Produkte umgewandelt werden kann. Wir stellen Beispiele selektiver Katalysen vor und hoffen, dass die bisher erzielten Fortschritte ermutigend für das Gebiet sind. Zugleich wollen auch die noch offenen Fragen beim Entwurf und dem mechanistischen Verständnis selektiver Katalysatoren thematisieren.

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Iridium‐Catalyzed CH Activation versus Directed ortho Metalation: Complementary Borylation of Aromatics and Heteroaromatics

Cited by 111 publications

References 60 publications

Achieving High Ortho Selectivity in Aniline C–H Borylations by Modifying Boron Substituents

Achieving High Ortho Selectivity in Aniline C–H Borylations by Modifying Boron Substituents

Recent advances in the C–H-functionalization of the distal positions in pyridines and quinolines

Katalytische selektive Synthese

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