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[摘要]：An extensive joint experimental-computational density functional theory (DFT) study has been carried out to gain insight into the factors that control the chemoselectivity (i.e., acylation vs alpha-arylation reaction) of palladium-catalyzed cyclizations of (2-iodoanilino)-aldehydes. To this end, the nature of the tethers joining the aniline nitrogen and the aldehyde moiety, different palladium precatalysts and reaction conditions (base and temperature), as well as different additives (mono- and bidendate ligands) has been explored. The adequate selection of these variables allows for the control of the selectivity of the process. Thus, (2-iodoanilino)-aldehydes generally lead to the formation of nucleophilic addition derived products when Cs2CO3/Et3N is used as base. In contrast, the use of stronger bases like (KOBu)-O-t (in the presence of PhOH) mainly forms alpha-arylation reaction products. The different reaction pathways leading to the experimentally observed reaction products have been studied by means of computational tools. |
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