Insight into the mechanism of the catalysis of urethane formation by organotin(IV) dicarboxylate

Devendra, Ransi; Edmonds, Neil R.; Söhnel, Tilo

doi:10.1007/s11144-018-1366-4

Cited by 6 publications

(11 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These mechanisms are different from what had been suggested previously based on using only classical methods [9]. Our calculations also revealed that the N-coordinated interaction has a lower transition state energy compared to the O-coordinated interaction in the insertion step [8].…”

Section: Introductioncontrasting

confidence: 99%

“…The transition state for O-coordinated interactions for both aliphatic and aromatic isocyanates gave higher activation free energies compared to Ncoordinated interactions [8]. Therefore, we will focus on the N-coordinated form.…”

Section: Methyl Isocyanate N-coordinated Interaction With Alcoholisedmentioning

confidence: 99%

“…In partway 1, the interaction will lead to the formation of urethane by an interaction between the organotin carbamate formed with the free carboxylic acid molecule by first forming the pre-complex_acid (8). In pathway 2, the organotin carbamate will interact with alcohol which is present in stoichiometric excess by first forming the pre_complex_alcohol (11) to give the free organotin alkoxide and the urethane.…”

Section: Methyl Isocyanate N-coordinated Interaction With Alcoholisedmentioning

confidence: 99%

“…In pathway 2, the organotin carbamate will interact with alcohol which is present in stoichiometric excess by first forming the pre_complex_alcohol (11) to give the free organotin alkoxide and the urethane. The two pathways will be governed by the stability of complexes (8) and (11), respectively, formed between free carboxylic acid and the organotin carbamate or the alcohol and the organotin carbamate. It can be seen from Tables 3 and 4 that the free energy difference for the formation of complex (8) (1.3 kJ mol À1 ) is significantly less than of complex (11) (14.7 kJ mol À1 ).…”

Section: Methyl Isocyanate N-coordinated Interaction With Alcoholisedmentioning

confidence: 99%

“…However, based on computational and experimental results, we have recently proposed mechanisms for the catalytic processes of the formation of urethanes. Organotin dicarboxylate was used as catalyst in combination with aliphatic and aromatic isocyanates [6,7,8]. In this work, the DFT B3LYP functional was used with LAN2DZ and 6-31G* basis sets for tin and light elements, respectively, and both geometrical and thermodynamic data were used to explain experimental findings.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Investigations of catalysis of urethane formation using organotin dicarboxylate

Devendra

Edmonds

Söhnel

2020

Heliyon

Self Cite

View full text Add to dashboard Cite

The reaction mechanism of the urethane formation for both aliphatic and aromatic isocyanates in the presence of organotin dicarboxylate as a catalyst is investigated theoretically and experimentally. Modelling on a dispersion corrected DFT level of theory (B3LYP-D3) shows that an alkoxide complex is formed between organotin dicarboxylate and alcohol. This complex is the dominant catalyst for the urethane formation reaction. In this study, the interaction between the alkoxide complex and isocyanate through N-coordination is considered. By using thermochemical data, it is possible to show that aliphatic isocyanates can be more sensitive to the carboxylic ligand content of the organotin compound as a catalyst in urethane formation in non-polar solvents compared to aromatic isocyanates. The interactions of carboxylic acid, which is formed as an intermediate in the catalysis process, with isocyanate and the effects on the catalytic process are also discussed.

show abstract

Section: Introductioncontrasting

confidence: 99%

Section: Methyl Isocyanate N-coordinated Interaction With Alcoholisedmentioning

confidence: 99%

Section: Methyl Isocyanate N-coordinated Interaction With Alcoholisedmentioning

confidence: 99%

Section: Methyl Isocyanate N-coordinated Interaction With Alcoholisedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Investigations of catalysis of urethane formation using organotin dicarboxylate

Devendra

Edmonds

Söhnel

2020

Heliyon

Self Cite

View full text Add to dashboard Cite

show abstract

Synthesis and structural characterization of diorganotin(IV) complexes with a tridentate N‐heterocyclic podand ligand and investigation of their catalytic activity in Baeyer–Villiger oxidation of cyclic ketones to lactones

Basu Baul,

Khatiwara,

Addepalli

et al. 2023

Applied Organom Chemis

View full text Add to dashboard Cite

Diorganotin(IV) complexes of composition [Me2SnL] (1), [n‐Bu2SnL] (2), and [Bz2SnL] (3) were synthesized by reacting the N2,N6‐di(pyridin‐2‐yl)pyridine‐2,6‐dicarboxamide pro‐ligand (H2L, where H2 denotes the two acidic protons) with Me2SnO, n‐Bu2SnO, and Bz2SnO, respectively, in refluxing toluene. The amide ligand leads to highly stable diorganotin(IV) complexes via the dianionic tridentate donor set (Npy, N−, N−) with pendent pyridine arms, and the coordination domain is completed by the respective two alkyl ligands. Solution‐state structures of the compounds 1–3 were studied by 1H, 13C, and 119Sn nuclear magnetic resonance (NMR) spectroscopy, revealing that the complexes adopt a five‐coordinate structure in non‐coordinating solvent. Additionally, homogenity and purity of the bulk materials of 1–3 were judged using the high‐resolution mass spectrometry in acetonitrile solution. The molecular and crystal structures of 1·0.5C6H6, 2, and 3 in the solid phase were established by single‐crystal X‐ray diffraction analysis. For all three compounds, the core defined by the rigid tridentate pyridine dicarboxamide ligand and the Sn‐coordinating C atoms adopts nearly C2v symmetry and thus matches none of the most popular geometries for five‐coordinated species, namely square‐pyramidal or trigonal‐bipyramidal coordination. Thermogravimetric analysis (TGA) was performed to probe the thermal stabilities of 1–3. The results serve as a basis for designing highly efficient diorganotin(IV) mimics for catalytic applications. Catalytic studies of ε‐caprolactone formation via Baeyer–Villiger oxidation of cyclohexanone with aqueous H2O2 were performed under microwave (MW) irradiation. The consequences of several reaction parameters like catalyst quantity, time, temperature, and solvent were studied.

show abstract