Activation of Dinitrogen‐Derived Hafnium Nitrides for Nucleophilic NC Bond Formation with a Terminal Isocyanate

Semproni, Scott P.; Chirik, Paul J.

doi:10.1002/ange.201307097

Cited by 18 publications

(4 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the hafnocene nitrides with 4-substituded pyridine donors were unreactive toward CO 2 , nitriles, and alkynes, 141 the parent pyridine derivative [{(η 5 142 Depending on the stoichiometry of the reaction, either [{(η 5 -…”

Section: Interaction Of N 2 With Transition Metalsmentioning

confidence: 99%

“…While the hafnocene nitrides with 4-substituded pyridine donors were unreactive toward CO 2 , nitriles, and alkynes, the parent pyridine derivative [{(η 5 -C 5 H 2 -1,2,4-Me 3 ) 2 Hf} 2 (μ 2 ,η 2 ,η 2 -N 2 )](C 5 H 5 N) and the hafnocene without stabilizing donor [{(η 5 -C 5 H 2 -1,2,4-Me 3 ) 2 Hf} 2 (NCO)(μ 2 -N)] share a more pronounced and diverse nitrogen functionalization chemistry. − As shown in Scheme , addition of MeOTf to the pyridine stabilized complex [{(η 5 -C 5 H 2 -1,2,4-Me 3 ) 2 Hf} 2 (μ 2 ,η 2 ,η 2 -N 2 )](C 5 H 5 N) produced N–C bond formation between the isocyanate and the nitride ligand to the corresponding ureates [{(η 5 -C 5 H 2 -1,2,4-Me 3 ) 2 Hf} 2 (μ 2 -OTf)(μ 2 -NCONX)] (X = H or Me) …”

Section: N–x Bond Formation With Retention Of the N–n Bondmentioning

confidence: 99%

See 1 more Smart Citation

Beyond Ammonia: Nitrogen–Element Bond Forming Reactions with Coordinated Dinitrogen

2020

Self Cite

View full text Add to dashboard Cite

The functionalization of coordinated dinitrogen to form nitrogen–element bonds en route to nitrogen-containing molecules is a long-standing challenge in chemical synthesis. The strong triple bond and the nonpolarity of the N2 molecule pose thermodynamic and kinetic challenges for promoting reactivity. While heterogeneous, homogeneous, and biological catalysts are all known for catalytic nitrogen fixation to ammonia, the catalytic synthesis of more complicated nitrogen-containing organic molecules has far less precedent. The example of silyl radical additions to coordinated nitrogen to form silylamines stands as the lone example of a catalytic reaction involving N2 to form a product other than ammonia. This Review surveys the field of molecular transition metal complexes as well as recent boron examples for the formation of nitrogen–element bonds. Emphasis is placed on the coordination and activation modes of N2 in the various metal compounds from across the transition series and how these structures can rationally inform reactivity studies. Over the past few decades, the field has evolved from the addition of carbon electrophiles in a manner similar to that of protonation reactions to more organometallic-inspired reactivity, including insertions, 1,2-additions, and cycloadditions. Various N–C, N–Si, and N–B bond-forming reactions have been discovered, highlighting that the challenge for catalytic chemistry is not in the reactivity of coordinated dinitrogen but rather removal of the functionalized ligand from the coordination sphere of the metal.

show abstract

Section: Interaction Of N 2 With Transition Metalsmentioning

confidence: 99%

Section: N–x Bond Formation With Retention Of the N–n Bondmentioning

confidence: 99%

Beyond Ammonia: Nitrogen–Element Bond Forming Reactions with Coordinated Dinitrogen

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…6 More recently, Chirik reported that side-on bound N2 complexes can react with a wider range of reagents to form N-C bonds. [71][72][73][74] In the reaction described here, the distinctive feature is the partial reduction of N2 prior to its functionalization. This is valuable because it is not necessary for the metal-N2 complex to be particularly reactive; the N2 is rendered reactive through reduction/silylation.…”

Section: Mechanistic Evaluation Using Computationsmentioning

confidence: 99%

Mechanism of Nitrogen-Carbon Bond Formation From Iron(IV) Disilylhydrazido Intermediates During N2 Reduction

Bhutto

Hooper

Mercado

et al. 2022

Preprint

View full text Add to dashboard Cite

We recently reported a reaction sequence that activates C–H bonds in simple arenes as well as the N–N triple bond in N2, delivering the aryl group to N2 to form a new N–C bond. This enables the transformation of abundant feedstocks (arenes and N2) into N-containing organic compounds. The key N–C bond forming step occurs upon partial silylation of N2, which then can accept the aryl fragment. However, the pathway through which reduction, silylation, and migration occurred was unknown. Here we describe synthetic, structural, magnetic, spectroscopic, kinetic, and computational studies that elucidate the steps of this transformation. N2 must be silylated twice at the distal N atom before aryl migration can occur, and sequential silyl radical and silyl cation addition is a kinetically competent pathway to a formally iron(IV) intermediate with an NN(SiMe3)2 ligand. It can be isolated at low temperature. Kinetic studies show its first-order conversion to the migrated product, and DFT calculations indicate a concerted transition state for migration. The electronic structure of the formally iron(IV) intermediate is examined using DFT and CASSCF calculations, which reveal contributions from iron(II) and iron(III) resonance forms with oxidized NNSi2 ligands. The depletion of electron density from the Fe-coordinated N atom makes it electrophilic enough to accept the incoming aryl group. This unprecedented pathway for N–C bond formation offers a method for functionalizing N2 with organometallic chemistry.

show abstract

“…Direct conversion of N 2 into high-value N-containing organic compounds, not through NH 3 , is of great significance and challenging both fundamentally and practically . Although some progress in making C–N bonds through N 2 –transition metal − or N 2 –actinide complexes and carbon-based reagents have been reported in the literature, such an approach is still in its infancy. As a class of important synthetic intermediates, hydrazine derivatives, which may contain up to four C–N bonds on the N–N single-bond skeleton, are primary targets for direct conversion of N 2 (Scheme ).…”

mentioning

confidence: 99%

Scandium-Promoted Direct Conversion of Dinitrogen into Hydrazine Derivatives via N–C Bond Formation

Huang

Zhang

et al. 2019

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Direct conversion of dinitrogen (N 2 ) into organic compounds, not through ammonia (NH 3 ), is of great significance both fundamentally and practically.Here we report a highly efficient scandium-mediated synthetic cycle affording hydrazine derivatives (RMeN− NMeR′) directly from N 2 and carbon-based electrophiles. The cycle includes three main steps: (i) reduction of a halogen-bridged discandium complex under N 2 leading to a (N 2 ) 3− -bridged discandium complex via a (N 2 ) 2− intermediate; (ii) treatment of the (N 2 ) 3− complex with methyl triflate (MeOTf), affording a (N 2 Me 2 ) 2− -bridged discandium complex; and (iii) further reaction of the (N 2 Me 2 ) 2− complex with the carbon-based electrophile, producing the hydrazine derivative and regenerating the halide precursor. Furthermore, insertion of a CO molecule into one Sc−N bond in the (N 2 Me 2 ) 2− −scandium complex was observed. Most notably, this is the first example of rare-earth metal-promoted direct conversion of N 2 to organic compounds; the formation of C−N bonds by the reaction of these (N 2 ) 3− and (N 2 Me 2 ) 2− complexes with electrophiles represents the first case among all N 2 − metal complexes reported.

show abstract

Activation of Dinitrogen‐Derived Hafnium Nitrides for Nucleophilic NC Bond Formation with a Terminal Isocyanate

Cited by 18 publications

References 41 publications

Beyond Ammonia: Nitrogen–Element Bond Forming Reactions with Coordinated Dinitrogen

Beyond Ammonia: Nitrogen–Element Bond Forming Reactions with Coordinated Dinitrogen

Mechanism of Nitrogen-Carbon Bond Formation From Iron(IV) Disilylhydrazido Intermediates During N2 Reduction

Scandium-Promoted Direct Conversion of Dinitrogen into Hydrazine Derivatives via N–C Bond Formation

Contact Info

Product

Resources

About