Xiaofan Shi, Yaqi Zhao, Ying Zhou, Zhewei Li, Yanhui Tang, Hongyuan Fu, Yangqiu Liu, Zhi-Guo Zhang, Min Pu, Ming Lei
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引用次数: 0
Abstract
Herein, the reaction mechanism for the GaCl3-catalyzed Knoevenagel condensation of 2-formylindacenodithieno[3,2-b]thiophene (ITIC-CHO) and active methylene compound 1,1-dicyanomethylene-3-indanone (IC) to synthesize ITIC in the presence of acetic anhydride was investigated using the density functional theory (DFT) method. The calculated results indicate that this reaction follows a bimolecular GaCl3 catalytic mechanism. The free energy span for the monomolecular GaCl3 catalytic mechanism is the highest (31.8 kcal/mol), followed by the trimolecular GaCl3 catalytic mechanism (26.4 kcal/mol) and the bimolecular GaCl3 catalytic mechanism (26.3 kcal/mol). The trimolecular GaCl3 path and bimolecular GaCl3 path are competitive, but the former path is limited by the concentration of GaCl3. The inclusion of GaCl3 could stabilize the transition states of C-H activation. Compared to the GaCl3-catalyzed Knoevenagel condensation, that catalyzed by pyridine is not advantageous, owning a high energy span of 31.7 kcal/mol. These agree well with experimental results. This work could provide a novel theoretical understanding of the Knoevenagel condensation, which could inspire the development of a synthesis strategy for electron acceptor materials.
期刊介绍:
The Journal of Organic Chemistry welcomes original contributions of fundamental research in all branches of the theory and practice of organic chemistry. In selecting manuscripts for publication, the editors place emphasis on the quality and novelty of the work, as well as the breadth of interest to the organic chemistry community.