Systematic study of aromatic-ring-targeted cycloadditions of HMF platform chemicals
The reaction space of the furanics-to-aromatics (F2A) conversion process for HMF-based platform chemicals has been explored both experimentally and by quantum chemistry methods. For the first time, a structure-activity relationship was established in furan-yne cycloaddition for a number of different HMF derivatives. Correlations between the activation energy of the cycloaddition stage and the structure of the substrates were established by molecular modeling methods. Analysis of the concerted and stepwise mechanisms of cycloaddition in the singlet and triplet electronic states of the molecular system was carried out. A series of biobased 7-oxanorbornadienes was obtained in the reaction with dimethyl acetylenedicarboxilate. Various methods of aromatization of the obtained [4+2] adducts have been examined. Rearrangement catalyzed by a Lewis acid leads to the formation of a phenol derivative, while reduction by diironnonacarbonyl leads to the formation of functionalized benzene. Systematic study of the cycloaddition process has revealed a simple way to analyze and predict the relative reactivity of furanic substrates.
Reference: ACS Sustainable Chem. Eng., 2021, ASAP
