24344-59-0Relevant articles and documents
Synthesis of Long-Chain Alkanoyl Benzenes by an Aluminum(III) Chloride-Catalyzed Destannylative Acylation Reaction
Roemer, Max,Keaveney, Sinead T.,Proschogo, Nicholas
, p. 9007 - 9022 (2021/07/20)
This paper describes the facile synthesis of haloaryl compounds with long-chain alkanoyl substituents by the destannylative acylation of haloaryls bearing tri-n-butyltin (Bu3Sn) substituents. The method allows the synthesis of many important synthons for novel functional materials in a highly efficient manner. The halo-tri-n-butyltin benzenes are obtained by the lithium-halogen exchange of commercially available bis-haloarenes and the subsequent reaction with Bu3SnCl. Under typical Friedel-Crafts conditions, i.e., the presence of an acid chloride and AlCl3, the haloaryls are acylated through destannylation. The reactions proceed fast (5 min) at low temperatures and thus are compatible with aromatic halogen substituents. Furthermore, the method is applicable topara-,meta-, andortho-substitution and larger systems, as demonstrated for biphenyls. The generated tin byproducts were efficiently removed by trapping with silica/KF filtration, and most long-chain haloaryls were obtained chromatography-free. Molecular structures of several products were determined by X-ray single-crystal diffraction, and the crystal packing was investigated by mapping Hirshfeld surfaces onto individual molecules. A feasible reaction mechanism for the destannylative acylation reaction is proposed and supported through density functional theory (DFT) calculations. DFT results in combination with NMR-scale control experiments unambiguously demonstrate the importance of the tin substituent as a leaving group, which enables the acylation.
