Computational mechanistic studies of the carbon–carbon double bond difunctionalization via epoxidation and subsequent aminolysis in vegetable oils. Issue 10 (2nd February 2021)

• Record Type: Journal Article
• Authors: Abdullayev, Yusif; Abbasov, Vagif; Nasirov, Fuzuli; Rzayeva, Nigar; Nasibova, Leyla; Autschbach, Jochen
• Is Part Of: International journal of quantum chemistry. Volume 121:Issue 10(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-02
• Subjects: CC double bond -- catalyst -- DFT -- energetic span -- epoxide ring‐opening; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.26609
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: The industrial importance of the CC double bond difunctionalization in vegetable oils/fatty acid chains motivates computational studies aimed at helping to improve experimental protocols. The CC double bond epoxidation is studied with hydrogen peroxide, peracetic acid (CH3 CO3 H), and performic acid (HCO3 H) oxidizing agents. The epoxide ring‐opening mechanism is calculated in the presence of ZnCl2, NiCl2, and FeCl2 Lewis acidic catalysts. Computations show that H2 O2 (∆ G ‡ = 39 kcal/mol, TS1 HP ) is not an effective oxidizing agent compared to CH3 CO3 H (∆ G ‡ = 29.8 kcal/mol, TS1 PA ) and HCO3 H (∆ G ‡ = 26.7 kcal/mol, TS1 PF ). The FeCl2 (∆ G ‡ = 14.7 kcal/mol, TS1 FC ) coordination to the epoxide oxygen facilitates the ring‐opening via lower energy barriers compared to the ZnCl2 (∆ G ‡ = 19.5 kcal/mol, TS1 ZC ) and NiCl2 (∆ G ‡ = 29.4 kcal/mol, TS1 NC ) coordination. ZnCl2 was 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. Abstract : A mechanism of the carbon–carbon double bond epoxidation and the epoxide ring‐opening is studied computationally. Performic acid (∆ G ‡ = 26.7 kcal/mol) is found to be a very good oxidizing agent for the CC epoxidation compared to peracetic acid and hydrogen peroxide. The applied energetic span model and calculated TOF values suggest FeCl2 as an efficient catalyst relative to NiCl2 and ZnCl2 for the epoxide ring‐opening reaction.