Boryl ligands and their roles in metal-catalysed borylation reactions

Dang, Li; Lin, Zhenyang; Marder, Todd B.

doi:10.1039/b903098k

Cited by 331 publications

(202 citation statements)

References 203 publications

Supporting

Mentioning

192

Contrasting

Unclassified

Order By: Relevance

“…The polarity of the rhodiumboron bond in 3, based on the calculated natural charges, is reasonable, considering the smaller electronegativity and strong σ-donor ability of a boryl ligand. 34 An alternative mechanism from 1 to 3 involves concerted σ-bond metathesis between 1 and diboron. However, geometry optimization of a four-membered transition state TS 13 led to the formation of a three-centered TS 12 , indicating that TS 13 is disfavored compared with TS 12 .…”

mentioning

confidence: 99%

Theoretical Studies of Rhodium-Catalyzed Borylation of Nitriles through Cleavage of Carbon–Cyano Bonds

Kinuta

Takahashi

Tobisu

et al. 2014

Bulletin of the Chemical Society of Japan

View full text Add to dashboard Cite

Rhodium(I)-catalyzed borylation of nitriles is investigated theoretically, using the density functional theory method, to clarify the reaction mechanism, including the formation process of the catalytically active species, carboncarbon bond cleavage, and the effect of an amine additive. The initial step in this reaction is the formation of a borylrhodium(I) species, in which the rhodium center carries a significant negative charge. The most energetically favorable pathway for carbon carbon bond cleavage involves the insertion of a cyano group into borylrhodium(I) to form an iminoacyl intermediate, followed by extrusion of boryl isocyanide (iminoacyl mechanism). The calculation suggests that DABCO can react with coproduced reactive boron species, such as boryl chloride and boryl isocyanide, to form stable adducts, lowering the energy of the entire reaction system. In addition, the chemoselectivities among CCN, CBr, and CCl bonds observed in experimental studies are in good agreement with the calculated activation energies required for these bond activation processes.The selective cleavage of carboncarbon σ-bonds and their transformations are among the most fundamental challenges in organic chemistry. Several transition-metal complexes have been reported to mediate such processes.1 However, it is generally difficult, even with transition-metal complexes, to activate simple carboncarbon σ-bonds because their nonpolar character and steric bulk around the sp 3 -hybridized carbon center make interactions with metal complexes difficult. Suitable substrates are therefore largely limited to those with ring strain or directing groups. The activation of carboncyano (CCN) bonds by transition metals has long been known to occur in the absence of ring strain, despite their high bond dissociation energies (ca. 130 kcal mol ¹1 for PhCN). 2 The relative easiness of these processes is attributed to the smaller steric congestion of an sp-hybridized cyano carbon and to the metal-coordinating ability of the neighboring carbonnitrogen triple bond. Metal-mediated CCN bond activation has been successfully used in catalytic transformations of nitriles.

show abstract

mentioning

confidence: 99%

Theoretical Studies of Rhodium-Catalyzed Borylation of Nitriles through Cleavage of Carbon–Cyano Bonds

Kinuta

Takahashi

Tobisu

et al. 2014

Bulletin of the Chemical Society of Japan

View full text Add to dashboard Cite

show abstract

“…[4] Das einfache Boryl-Anion in der Boryllithiumverbindung C [5] ist seit 2006 bekannt. Sein anionisches Borzentrum wirkt gegenüber vielen Elektrophilen als Nucleophil, und durch Transmetallierungen sind entsprechende Borylmetallspezies zugänglich.…”

unclassified

Nucleophilie des Borzentrums in Base‐stabilisierten Borol‐Anionen

Yamashita

2010

Angewandte Chemie

View full text Add to dashboard Cite

“…[19] o-Phenylendiamin wird durch Kondensation mit Formaldehyd und dem sekundären Phosphan mit guter Ausbeute in das Bis(di-tertbutylphosphanylmethyl)-Analogon 8 umgewandelt (Schema 3). Der anschließende Ringschluss der beiden Aminogruppen unter Verwendung von basestabilisiertem BH 3 ·SMe 2 im Überschuss lieferte das gewünschte Hydro(diamino)boran 9 mit 78 % nach Entschützung der Phosphangruppen; das 11 …”

unclassified

Boryl‐Pinzettensysteme: neue Wege in der Borchemie

Vlugt¹

2009

Angewandte Chemie

View full text Add to dashboard Cite

Bor in zentraler Rolle: Die Integration einer BH‐Einheit in einen dreizähnigen Liganden führte kürzlich zur Isolierung der ersten Komplexe mit Boryl‐Pinzettenliganden. Funktionalisierte m‐Carbaborane und Diaminoborane (siehe Bild) bilden Palladium‐ bzw. Iridium‐Komplexe. Als Ergebnis der Metall‐Boryl‐Bindung und der elektronischen Kommunikation mit dem Ligandengerüst ist eine neue Reaktivität, auch in der Katalyse, zu erwarten.

show abstract

Boryl ligands and their roles in metal-catalysed borylation reactions

Cited by 331 publications

References 203 publications

Theoretical Studies of Rhodium-Catalyzed Borylation of Nitriles through Cleavage of Carbon–Cyano Bonds

Theoretical Studies of Rhodium-Catalyzed Borylation of Nitriles through Cleavage of Carbon–Cyano Bonds

Nucleophilie des Borzentrums in Base‐stabilisierten Borol‐Anionen

Boryl‐Pinzettensysteme: neue Wege in der Borchemie

Contact Info

Product

Resources

About