Thorium(IV) alkyl synthesis from a thorium(III) cyclopentadienyl complex and an N-heterocyclic olefin

Liu, Jingjing; Seed, John A.; Formanuik, Alasdair; Ortu, Fabrizio; Wooles, Ashley J.; Mills, David P.; Liddle, Stephen T.

doi:10.1016/j.jorganchem.2017.08.015

Cited by 11 publications

(12 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The authors discussed potential reaction pathways, and it seems obvious that an N-methyl substitutent is transferred from the NHO and that the resulting radical is trapped by dimerization. 211 The same NHO ligand 115 was employed for the reaction with the rare-earth metal and actinide triamides [M{N(SiMe 3 ) 2 } 3 ] (134, M = Y, La, Nd, U). In contrast to results reported previously by Schumann and Kuhn for [( Me IMe)CH 2 ] (108, vide supra), 196 no NHO complexes could be isolated, and the formation of the mesoionic carbene (MIC, or abnormal carbene) complexes 135 was observed instead (Scheme 37).…”

Section: Chemical Reviewscontrasting

confidence: 82%

“…Instead of NHO coordination, methylation and formation of the thorium(IV) complex [(η 5 -Cp′′) 3 Th(CH 3 )] was observed. The authors discussed potential reaction pathways, and it seems obvious that an N -methyl substitutent is transferred from the NHO and that the resulting radical is trapped by dimerization . The same NHO ligand 115 was employed for the reaction with the rare-earth metal and actinide triamides [M{N(SiMe 3 ) 2 } 3 ] ( 134 , M = Y, La, Nd, U).…”

Section: N-heterocyclic Carbene Adducts Of Group 14 Elementsmentioning

confidence: 99%

See 1 more Smart Citation

N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry

2019

View full text Add to dashboard Cite

N-Heterocyclic carbenes (NHC) are nowadays ubiquitous and indispensable in many research fields, and it is not possible to imagine modern transition metal and main group element chemistry without the plethora of available NHCs with tailor-made electronic and steric properties. While their suitability to act as strong ligands toward transition metals has led to numerous applications of NHC complexes in homogeneous catalysis, their strong σ-donating and adaptable π-accepting abilities have also contributed to an impressive vitalization of main group chemistry with the isolation and characterization of NHC adducts of almost any element. Formally, NHC coordination to Lewis acids affords a transfer of nucleophilicity from the carbene carbon atom to the attached exocyclic moiety, and low-valent and lowcoordinate adducts of the p-block elements with available lone pairs and/or polarized carbon-element π-bonds are able to act themselves as Lewis basic donor ligands toward transition metals. Accordingly, the availability of a large number of novel NHC adducts has not only produced new varieties of already existing ligand classes but has also allowed establishment of numerous complexes with unusual and often unprecedented element−metal bonds. This review aims at summarizing this development comprehensively and covers the usage of N-heterocyclic carbene adducts of the p-block elements as ligands in transition metal chemistry.

show abstract

Section: Chemical Reviewscontrasting

confidence: 82%

Section: N-heterocyclic Carbene Adducts Of Group 14 Elementsmentioning

confidence: 99%

N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry

2019

View full text Add to dashboard Cite

show abstract

“…In fact, the addition of a slight excess amount of 3 to [An{N(SiMe 3 ) 2 } 2 (CH 2 SiMe 2 NSiMe 3 )] ( 6M ) on an NMR scale results in the formation of 4M suggesting that the cyclometallation of 2M prior to rearrangement and subsequent coordination of 3 is a reasonable mechanistic suggestion (Figures S2 and S3 in the Supporting Information). We also note that when treating [Th{η 5 -C 5 H 3 (1,3-SiMe 3 ) 2 } 3 ], which is the cyclopentadienyl analogue of [U{N(SiMe 3 ) 2 } 3 ], that is, the direct precursor to 1 , no MIC formation is observed . However, it is currently not possible to discount a bimetallic mechanism or one where coordinated 3 is deprotonated by free 3 followed by isomerization and reprotonation.…”

Section: Results and Discussionsupporting

confidence: 73%

“…We also note that when treating [Th{η 5 -C 5 H 3 (1,3-SiMe 3 ) 2 } 3 ], which is the cyclopentadienyl analogue of [U{N(SiMe 3 ) 2 } 3 ], that is, the direct precursor to 1 , no MIC formation is observed. 13 However, it is currently not possible to discount a bimetallic mechanism or one where coordinated 3 is deprotonated by free 3 followed by isomerization and reprotonation.…”

Section: Results and Discussionmentioning

confidence: 99%

Mesoionic Carbene Complexes of Uranium(IV) and Thorium(IV)

et al. 2022

Self Cite

View full text Add to dashboard Cite

We report the synthesis and characterization of uranium(IV) and thorium(IV) mesoionic carbene complexes [An{N(SiMe 3 ) 2 } 2 (CH 2 SiMe 2 NSiMe 3 ){MIC}] (An = U, 4U and Th, 4Th ; MIC = {CN(Me)C(Me)N(Me)CH}), which represent rare examples of actinide mesoionic carbene linkages and the first example of a thorium mesoionic carbene complex. Complexes 4U and 4Th were prepared via a C–H activation intramolecular cyclometallation reaction of actinide halides, with concomitant formal 1,4-proton migration of an N -heterocyclic olefin (NHO). Quantum chemical calculations suggest that the An–carbene bond comprises only a σ-component, in contrast to the uranium(III) analogue [U{N(SiMe 3 ) 2 } 3 (MIC)] ( 1 ) where computational studies suggested that the 5f 3 uranium(III) ion engages in a weak one-electron π-backbond to the MIC. This highlights the varying nature of actinide-MIC bonding as a function of actinide oxidation state. In solution, 4Th exists in equilibrium with the Th(IV) metallacycle [Th{N(SiMe 3 ) 2 } 2 (CH 2 SiMe 2 NSiMe 3 )] ( 6Th ) and free NHO ( 3 ). The thermodynamic parameters of this equilibrium were probed using variable-temperature NMR spectroscopy yielding an entropically favored but enthalpically endothermic process with an overall reaction free energy of Δ G 298.15K = 0.89 kcal mol –1 . Energy decomposition analysis (EDA-NOCV) of the actinide–carbon bonds in 4U and 4Th reveals that the former is enthalpically stronger and more covalent than the latter, which accounts for the respective stabilities of these two complexes.

show abstract

“…The resulting palladium complexes were active and recoverable catalysts for constructing C−C, C−O, and C−N bond . Afterwards, NHOs were introduced to the chemical community and employed widely in coordination chemistry . In very recent years, NHOs used as organocatalysts have been a hot topic in the field of organocatalysis .…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization of Pyridyl Heterocyclic Olefins (PHOs) and Activation of Heterocumulenes

Zhang

Wang

et al. 2019

ChemistrySelect

View full text Add to dashboard Cite

A series of new patterns of heterocyclic olefins (NHOs) based on pyridyl backbone were synthesized. Reactions of pyridyl heterocyclic olefins (PHOs) with heterocumulenes (CO2, CS2, isocyanate, isothiocyanate) afforded two different types of products including addition and insertion products. Insertion products represented rare example in such reactions. The reactivity between PHOs and heterocumulenes was primarily manipulated by the Lewis acidity of the heterocumulenes, while the product stability and selectivity were controlled by both the PHOs and heterocumulenes.

show abstract

Thorium(IV) alkyl synthesis from a thorium(III) cyclopentadienyl complex and an N-heterocyclic olefin

Abstract: ABSTRACT

Cited by 11 publications

References 73 publications

N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry

N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry

Mesoionic Carbene Complexes of Uranium(IV) and Thorium(IV)

Synthesis, Characterization of Pyridyl Heterocyclic Olefins (PHOs) and Activation of Heterocumulenes

Contact Info

Product

Resources

About