Implementation of Cooperative Designs in Polarized Transition Metal Systems—Significance for Bond Activation and Catalysis

Chatterjee, Basujit; Chang, Wei-Chieh; Jena, Soumyashree; Werlé, Christophe

doi:10.1021/acscatal.0c03794

Cited by 69 publications

(49 citation statements)

References 260 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A putative catalytic cycle for the hydrogenation of the formate ester to methanol is illustrated in Scheme 3 via the widely inferred metal–ligand cooperation (MLC) mechanism. 40 , 41 , 49 − 51 Plausible alternatives are, however, also conceivable, involving, for example, activation of the C=O unit by Na + instead of H + at the ligand amide group or heterolytic H 2 cleavage at a cationic Mn 1+ complex after carboxylate, alcoholate, or CO dissociation (see the Supporting Information for a schematic representation). 9 , 52 − 65 …”

Section: Resultsmentioning

confidence: 99%

Alcohol-Assisted Hydrogenation of Carbon Monoxide to Methanol Using Molecular Manganese Catalysts

Kaithal

Werlé

Leitner

2021

JACS Au

Self Cite

View full text Add to dashboard Cite

Alcohol-assisted hydrogenation of carbon monoxide (CO) to methanol was achieved using homogeneous molecular complexes. The molecular manganese complex [Mn(CO) 2 Br[HN(C 2 H 4 P i Pr 2 ) 2 ]] ([HN(C 2 H 4 P i Pr 2 ) 2 ] = MACHO- i Pr) revealed the best performance, reaching up to turnover number = 4023 and turnover frequency 857 h –1 in EtOH/toluene as solvent under optimized conditions ( T = 150 °C, p (CO/H 2 ) = 5/50 bar, t = 8–12 h). Control experiments affirmed that the reaction proceeds via formate ester as the intermediate, whereby a catalytic amount of base was found to be sufficient to mediate its formation from CO and the alcohol in situ . Selectivity for methanol formation reached >99% with no accumulation of the formate ester. The reaction was demonstrated to work with methanol as the alcohol component, resulting in a reactive system that allows catalytic “breeding” of methanol without any coreagents.

show abstract

Section: Resultsmentioning

confidence: 99%

Alcohol-Assisted Hydrogenation of Carbon Monoxide to Methanol Using Molecular Manganese Catalysts

Kaithal

Werlé

Leitner

2021

JACS Au

Self Cite

View full text Add to dashboard Cite

show abstract

“…The catalysts bearing these ligands effectively promote the reactions that involve hydride and proton management, such as (de)hydrogenation [1–11] and borrowing‐hydrogenation [12–16] . The nature (acid‐base properties) and the position/orientation of proton‐responsive unit, along with the metal‐hydricity, [17] are the key considerations to enable metal‐ligand cooperation (MLC) [18–20] for efficient hydrogen delivery/acceptance [21–24] . Among the various designs explored, the protic catalysts based on the reversible (de)protonation of −OH/=O, −CH 2 /=CH and −NH/=N motifs on pyridine, [25–27] bipyridine, [28–32] bipyrimidine [33] and azole‐pyridine/pyrimidine [34–37] are particularly effective.…”

Section: Introductionmentioning

confidence: 99%

A Proton‐Responsive Pyridyl(benzamide)‐Functionalized NHC Ligand on Ir Complex for Alkylation of Ketones and Secondary Alcohols

Kaur

Reshi

Patra

et al. 2021

Chemistry A European J

View full text Add to dashboard Cite

A Cp*Ir(III) complex (1) of a newly designed ligand L 1 featuring a proton-responsive pyridyl(benzamide) appended on N-heterocyclic carbene (NHC) has been synthesized. The molecular structure of 1 reveals a dearomatized form of the ligand. The protonation of 1 with HBF 4 in tetrahydrofuran gives the corresponding aromatized complex [Cp*Ir(L 1 H)Cl]BF 4 (2). Both compounds are characterized spectroscopically and by X-ray crystallography. The protonation of 1 with acid is examined by 1 H NMR and UV-vis spectra. The proton-responsive character of 1 is exploited for catalyzing α-alkylation of ketones and β-alkylation of secondary alcohols using primary alcohols as alkylating agents through hydrogen-borrowing methodology. Compound 1 is an effec-tive catalyst for these reactions and exhibits a superior activity in comparison to a structurally similar iridium complex [Cp*Ir(L 2 )Cl]PF 6 (3) lacking a proton-responsive pendant amide moiety. The catalytic alkylation is characterized by a wide substrate scope, low catalyst and base loadings, and a short reaction time. The catalytic efficacy of 1 is also demonstrated for the syntheses of quinoline and lactone derivatives via acceptorless dehydrogenation, and selective alkylation of two steroids, pregnenolone and testosterone. Detailed mechanistic investigations and DFT calculations substantiate the role of the proton-responsive ligand in the hydrogen-borrowing process.À OH/=O, À CH 2 /=CH and À NH/ = N motifs on pyridine, [25][26][27] bipyridine, [28][29][30][31][32] bipyrimidine [33] and azole-pyridine/ pyrimidine [34][35][36][37] are particularly effective. Some of the representative examples that have been employed for catalyzing (de) hydrogenation and alkylation reactions are given in Scheme 1. Yamaguchi and co-workers reported a Cp*Ir(III) compound with

show abstract

“…Since the free energy of mTSB2B3 is higher than that of TSC2C3 (27.9 vs 22.2 kcal/mol) in the rate‐determining step, the di ‐palladium catalysis is more favorable, and the calculations are well consistent with the experimental results that the catalytic activity of dinuclear palladium is higher than that of mononuclear palladium catalysis. The catalysis activity difference between dinuclear and mononuclear complex can be attributed to the roles of metal−metal cooperativity play in the activation of small molecules and the promotion and selectivity of subsequent catalytic transformations [53] …”

Section: Resultsmentioning

confidence: 99%

“…The catalysis activity difference between dinuclear and mononuclear complex can be attributed to the roles of metal À metal cooperativity play in the activation of small molecules and the promotion and selectivity of subsequent catalytic transformations. [53]…”

Section: Pyrrole Formation From T Bucn and Phenylacetylene Catalyzed By Mononuclear Palladium Complexmentioning

confidence: 99%

DFT Study on Dinuclear Palladium Complex Catalyzed Pyrrole Formation From tert‐Butyl Isocyanide and Alkynes

Lai

2021

ChemCatChem

View full text Add to dashboard Cite

Density functional theory calculations were carried out to study the mechanisms of Pd-catalyzed reactions of alkynes with tertbutyl isocyanide forming pyrroles. In the case of di-palladium catalysis, the calculations indicated that alkyne insertion, isocyanide insertion, intramolecular cyclization, isocyanide insertion, isomerization and ligand substitution were involved in the mechanism. The intramolecular cyclization process was calculated to be the rate-determining step in the catalytic cycle. The substituent effects on the regioselectivity of reaction were also analyzed. In addition, detailed calculations on monopalladium catalysis showed that the activity of mononuclear catalysis was not as high as that of di-palladium catalysis. These calculation results were in good agreement with the experimental results.

show abstract

Implementation of Cooperative Designs in Polarized Transition Metal Systems—Significance for Bond Activation and Catalysis

Cited by 69 publications

References 260 publications

Alcohol-Assisted Hydrogenation of Carbon Monoxide to Methanol Using Molecular Manganese Catalysts

Alcohol-Assisted Hydrogenation of Carbon Monoxide to Methanol Using Molecular Manganese Catalysts

A Proton‐Responsive Pyridyl(benzamide)‐Functionalized NHC Ligand on Ir Complex for Alkylation of Ketones and Secondary Alcohols

DFT Study on Dinuclear Palladium Complex Catalyzed Pyrrole Formation From tert‐Butyl Isocyanide and Alkynes

Contact Info

Product

Resources

About