Insights into the Halogen Effects on Regioselectivities of Nucleophilic Haloalkylation of α,β-Enones.

The halogen effects, specifically the replacement of chlorine with fluorine, on the shift in regioselectivity from 1,4- to 1,2-addition in the nucleophilic haloalkylation of α,β-enones have been investigated using density functional theory (DFT) calculations. Computational analysis revealed that the difluorocarbanion PhSOCF , being a hard nucleophile with lower energy of the highest occupied molecular orbital (HOMO), selectively undergoes 1,2-addition of chalcone, primarily dominated by Coulombic interactions. In contrast, the nucleophilic 1,4-addition of chalcone by a soft dichlorocarbanion PhSOCCl is controlled by frontier molecular orbital interactions.

Verification for Temperature Dependence of Tacticity in Polystyrene Radical Polymerization with the Combination of Reaction Pathway Analysis and Red Moon Methodology.

Radical polymerization is an economic and practical polymerization method over ionic and coordination polymerizations and is widely used for polymer production. Although many efforts have been made to improve the convenience and controllability of radical polymerization, it is still a challenge to directly observe the microbehaviors of propagation, which may provide inspiration for the development of polymerization processes. In this study, we focused on the tacticity of polystyrene produced by bulk radical polymerization since there is a debate over the temperature dependence.