Intermolecular C−H Bond Activation Promoted by a Titanium Alkylidyne

Bailey, Brad C.; Fan, Hongjun; Baum, Erich W.; Huffman, John C.; Baik, Mu‐Hyun; Mindiola, Daniel J.

doi:10.1021/ja0556934

Cited by 130 publications

(149 citation statements)

References 18 publications

(16 reference statements)

Supporting

Mentioning

137

Contrasting

Order By: Relevance

“…[75] A similar version of this reaction has also been observed between a titanium phosphinidene and N 2 CPh 2 . [78] The ability to generate transient titanium alkylidynes [119,120] [103] Another documented case of a Wittig-like reaction to produce titanium imides was reported by Richeson and coworkers. [54] In their studies a bis-guanidinate titanium bisalkyl underwent double insertion of a bulky isonitrile NCAr (Ar = 2,6-Me 2 C 6 H 3 ) to eventually afford the terminal aryl imide [{(Me 2 N)CA C H T U N G T R E N N U N G (NiPr 2 ) 2 } 2 Ti=NAr] (Scheme 25).…”

Section: Wittig-like Reactionsmentioning

confidence: 98%

The Progression of Synthetic Strategies to Assemble Titanium Complexes Bearing the Terminal Imide Group

Fout¹,

Kilgore²,

Mindiola³

2007

Chemistry A European J

View full text Add to dashboard Cite

The synthesis of terminal titanium imides is described in this account. The incorporation of this functional group has evolved from more simplistic approaches to more complex or unusual methods. Past and current synthetic strategies to incorporate the terminal imide functionality are explained with particular emphasis on low-coordinate titanium environments bearing this ubiquitous but vital type of motif. More recently, the imide functionality has demonstrated to be a key intermediate for modeling important industrial processes such as the hydrodenitrogenation of crude oil.

show abstract

Section: Wittig-like Reactionsmentioning

confidence: 98%

The Progression of Synthetic Strategies to Assemble Titanium Complexes Bearing the Terminal Imide Group

Fout¹,

Kilgore²,

Mindiola³

2007

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…Serving as a promising alternative of activating both sp 2 and sp 3 CH bonds under mild conditions, the mechanism of methane 1,2‐addition reaction via titanium alkylidyne intermediate, (PNP)TiC t Bu (PNP = N [2‐P i Pr 2 ‐4‐methylphenyl] 2 ‐ ), generated through α‐hydrogen abstraction from the titanium alkylidene (PNP)Ti = CH t Bu(

{CH}_{2}^{normalt}

Bu), has been investigated in both experiment and theory by Mindiola's group and Ninković et al As shown in Figure , the complex 1 features not only the less expensive titanium rather than those metals commonly utilized in CH activation, but also reverse hydrogen abstraction rather than photochemical activation in generating the transient titanium alkylidyne complex A, the involvement of which was validated in the CH activation of benzene and methane by Mindiola and coworkers experimentally, where the formation of complex A was demonstrated to be the rate‐determining step via mechanistic investigation.…”

Section: Introductionmentioning

confidence: 99%

Recent computational studies on transition‐metal carbon–hydrogen bond activation of alkanes

Guan

Zarić

Brothers

et al. 2018

Int J of Quantum Chemistry

View full text Add to dashboard Cite

This review on computational studies of transition-metal promoted CAH activation of light linear alkanes will cover computational work published since 2010, following upon seminal reviews by Niu and Hall (Chem. Rev. 2000, 100, 353), Vastine and Hall (Coord. Chem. Rev. 2009, 253, 1202), and Balcells et al. (Chem. Rev. 2010. The computational studies are surveyed in terms of the mechanistic nature of the CAH activation step (oxidative addition, r-bond metathesis, 1,2 addition, or electrophilic activation), the type of CAH bond being activated (primary or secondary), and the effect of metal, ligand, and alkane size on the reaction process. In addition to the primary focus on theoretical mechanistic investigations via calculated thermodynamics and kinetics, this review aims to bridge the computational and experimental observations and to highlight the insights that computational chemistry delivers to understanding the nature of CAH activation of linear alkanes mediated by transition metals.bond activation, carbon hydrogen bond, density functional 1 | I N TR ODU C TI ON Toward a deeper understanding of the mechanisms of organometallic reactions and catalysis, computational chemistry has long been recognized as a useful tool to characterize reactive species especially when data on such species are extremely difficult or impossible to obtain experimentally, such the geometric and electronic structure of transition states (TS). The computationally derived potential energy surfaces (PES) not only provides thermodynamic energetics that can be correlated with the experimental kinetics, but also provides insight into the structural nature of the reaction by locating the reactants, intermediates, and products connected by the TSs, and thus, delineates the full reaction mechanism in terms of bondbreaking and bond-forming steps, which may facilitate reaction design to improve the reactivity and selectivity. [1] Several reviews published at the end of the last decade [2][3][4][5][6][7] have shown the progress that computational chemistry has made to the field of CAH bond activation, where the mechanistic interpretation of the activation step has been enhanced to show how the active mechanism for a specific scenario can depend subtly on the metal, the metal's oxidation state, the ligand set, and the substrate. Furthermore, some remarkable improvements have been made in computational methodologies that have profoundly impacted the modeling of transition-metal reactivity.Although density functional theory (DFT) with the hybrid B3LYP functional is often utilized for theoretical investigations of the structure and reactivity of organometallic complexes, the deficiencies of this functional are not negligible for thermochemistry, especially for situations where dispersion interactions are important. [8] Nowadays, dispersion interactions can be treated by adding explicit dispersion corrections by Grimme, [9] to the functional, such as B97D, [10] xB97X-D, [11] or B3LYP-D3BG, [9a] or by employing a Minnesota functional, like M06 or it...

show abstract

“…However, the number of terminal trimethylsilylmethylidene metal complexes plummets dramatically when the metal in question represents the lighter congener for each group (e.g., Ti, V, Cr) [2,[15][16][17][18]. In contrast, group 4 transition metal compounds bearing the terminal trimethylsilylmethylidene ligand are even more scant, with the only reported examples (isolable) being the titanium and zirconium complexes (PNP)Ti@CHSiMe 3 (X) (PNP À = N[2-P(CHMe 2 ) 2 -4-methylphenyl] 2 ) [19][20][21][22]; X À = OTf [23], CH 2 SiMe 3 [17]) and [C 5 H 3 (SiMe 2 P i Pr 2 ) 2 ]Zr@CHSiMe 3 (Cl) [24,25], respectively. In most cases, the M = CHSiMe 3 functionality in question must be trapped or generated in situ, to avoid decomposition pathways from occurring [26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

“…The only examples of a titanium complexes bearing the terminal trimethylsilylmethylidene unit were recently reported by us, and involved the compounds (PNP)Ti@ CHSiMe 3 (X) (X À = OTf [23], CH 2 SiMe 3 [17]). Rothwell and co-workers have reported bridging trimethylsilylmethylidene complexes of titanium [30,31].…”

Section: Introductionmentioning

confidence: 99%

“…In the case of terminal and stable titanium trimethylsilylmethylidene complexes, spectroscopic discrepancies arise when these ligands are compared to the C-based neopentylidene analogues. When measured up against (PNP)Ti@CH t Bu(CH 2 t Bu), the alkylidene carbon resonance for (PNP)Ti@CHSiMe 3 (CH 2-SiMe 3 ) (310.5 ppm) shifts further downfield in the 13 C{ 1 H} NMR spectrum (D = 50.5 ppm) [17]. This parameter reflects the electronic effect imposed by the trimethylsilyl unit on the a-C.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Organometallic consequences of a redox reaction: Terminal trimethylsilylmethylidene titanium complexes prepared by a one-electron oxidation step

Basuli

Adhikari

Huffman

et al. 2007

Journal of Organometallic Chemistry

Self Cite

View full text Add to dashboard Cite

Intermolecular C−H Bond Activation Promoted by a Titanium Alkylidyne

Cited by 130 publications

References 18 publications

The Progression of Synthetic Strategies to Assemble Titanium Complexes Bearing the Terminal Imide Group

The Progression of Synthetic Strategies to Assemble Titanium Complexes Bearing the Terminal Imide Group

Recent computational studies on transition‐metal carbon–hydrogen bond activation of alkanes

Organometallic consequences of a redox reaction: Terminal trimethylsilylmethylidene titanium complexes prepared by a one-electron oxidation step

Contact Info

Product

Resources

About