Metal alkyls programmed to generate metal alkylidenes by α-H abstraction: prognosis from NMR chemical shift - Université de Montpellier Accéder directement au contenu
Article Dans Une Revue Chemical Science Année : 2018

Metal alkyls programmed to generate metal alkylidenes by α-H abstraction: prognosis from NMR chemical shift

Résumé

Metal alkylidenes, which are key organometallic intermediates in reactions such as olefination or alkene and alkane metathesis, are typically generated from metal dialkyl compounds [M](CH2R)2 that show distinctively deshielded chemical shifts for their α-carbons. Experimental solid-state NMR measurements combined with DFT/ZORA calculations and a chemical shift tensor analysis reveal that this remarkable deshielding originates from an empty metal d-orbital oriented in the M–Cα–Cα′ plane, interacting with the Cα p-orbital lying in the same plane. This π-type interaction inscribes some alkylidene character into Cα that favors alkylidene generation via α-H abstraction. The extent of the deshielding and the anisotropy of the alkyl chemical shift tensors distinguishes [M](CH2R)2 compounds that form alkylidenes from those that do not, relating the reactivity to molecular orbitals of the respective molecules. The α-carbon chemical shifts and tensor orientations thus predict the reactivity of metal alkyl compounds towards alkylidene generation.

Domaines

Chimie
Fichier principal
Vignette du fichier
c7sc05039a.pdf (1.79 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Loading...

Dates et versions

hal-01710047 , version 1 (06-07-2020)

Licence

Paternité

Identifiants

Citer

Christophe Gordon, Keishi Yamamoto, Keith Searles, Satoru Shirase, Richard A Andersen, et al.. Metal alkyls programmed to generate metal alkylidenes by α-H abstraction: prognosis from NMR chemical shift. Chemical Science, 2018, 9 (7), pp.1912 - 1918. ⟨10.1039/c7sc05039a⟩. ⟨hal-01710047⟩
133 Consultations
57 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More