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Abstract The industrial importance of the CC double bond difunctionalization in vegetable oils/fatty acid chains motivates computational studies aimed at helping to improve experimental protocols. The CC double bond epoxidation is studied with hydrogen peroxide, peracetic acid (CH3CO3H), and performic acid (HCO3H) oxidizing agents. The epoxide ring‐opening mechanism is calculated in the presence of ZnCl2, NiCl2, and FeCl2Lewis acidic catalysts. Computations show that H2O2(∆G‡= 39 kcal/mol,TS1HP) is not an effective oxidizing agent compared to CH3CO3H (∆G‡= 29.8 kcal/mol,TS1PA) and HCO3H (∆G‡= 26.7 kcal/mol,TS1PF). The FeCl2(∆G‡= 14.7 kcal/mol,TS1FC) coordination to the epoxide oxygen facilitates the ring‐opening via lower energy barriers compared to the ZnCl2(∆G‡= 19.5 kcal/mol,TS1ZC) and NiCl2(∆G‡= 29.4 kcal/mol,TS1NC) coordination. ZnCl2was frequently utilized as a catalyst in laboratory‐scale procedures. The energetic span model identifies the FeCl2(FC) catalytic cycle as the best option for the epoxide ring‐opening.
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London Dispersion Effects in a Distannene/Tristannane Equilibrium: Energies of their Interconversion and the Suppression of the Monomeric Stannylene Intermediate
Abstract Reaction of {LiC6H2−2,4,6‐Cyp3⋅Et2O}2(Cyp=cyclopentyl) (1) of the new dispersion energy donor (DED) ligand, 2,4,6‐triscyclopentylphenyl with SnCl2afforded a mixture of the distannene {Sn(C6H2−2,4,6‐Cyp3)2}2(2), and the cyclotristannane {Sn(C6H2−2,4,6‐Cyp3)2}3(3).2is favored in solution at higher temperature (345 K or above) whereas3is preferred near 298 K. Van't Hoff analysis revealed the3to2conversion has a ΔH=33.36 kcal mol−1and ΔS=0.102 kcal mol−1 K−1, which gives a ΔG300 K=+2.86 kcal mol−1, showing that the conversion of3to2is an endergonic process. Computational studies show that DED stabilization in3is −28.5 kcal mol−1per {Sn(C6H2−2,4,6‐Cyp3)2unit, which exceeds the DED energy in2of −16.3 kcal mol−1per unit. The data clearly show that dispersion interactions are the main arbiter of the3to2equilibrium. Both2and3possess large dispersion stabilization energies which suppress monomer dissociation (supported by EDA results).
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- Award ID(s):
- 2152760
- PAR ID:
- 10413037
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 62
- Issue:
- 22
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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