We report on the phosphine-catalyzed intermolecular carbofluorination of alkynes using acyl fluorides as fluorinating reagents. This reaction promises to be a useful method for the synthesis of highly substituted monofluoroalkene derivatives, since acyl fluorides can be easily prepared from the corresponding carboxylic acid derivatives and the reaction proceeds under ambient conditions without the need for a transition-metal catalyst. Experimental and computational studies indicate that a five-coordinated fluorophosphorane is involved as the key intermediate in the fluorination step. File list (2) download file view on ChemRxiv SI_full_Fujimoto_acylfluorination0612.pdf (3.65 MiB) download file view on ChemRxiv Main_text_Fujimoto_carbofluorination_0612.pdf (391.19 KiB)

Herein, we describe a new catalytic approach to accessing aromatic amines from an abundant feedstock, namely phenols. The most reliable catalytic method for converting phenols to aromatic amines uses an activating group, such as a trifluoromethane sulfonyl group. However, this activating group is eliminated as a leaving group during the amination process, resulting in significant waste. Our nickel-catalyzed decarboxylation reaction of aryl carbamates forms aromatic amines with carbon dioxide as the only byproduct. As this amination proceeds in the absence of free amines, a range of functionalities, including a formyl group, are compatible. A bisphosphine ligand immobilized on a polystyrene support (PS-DPPBz) is key to the success of this reaction, generating a catalytic species that is significantly more active than simple nonsupported variants.

We report on the phosphine-catalyzed intermolecular carbofluorination of alkynes using acyl fluorides as fluorinating reagents. This reaction promises to be a useful method for the synthesis of highly substituted monofluoroalkene derivatives, since acyl fluorides can be easily prepared from the corresponding carboxylic acid derivatives and the reaction proceeds under ambient conditions without the need for a transition-metal catalyst. Experimental and computational studies indicate that a five-coordinated fluorophosphorane is involved as the key intermediate in the fluorination step.

We report on the N-heterocyclic carbene (NHC)-catalyzed Truce–Smiles rearrangement of aniline derivatives, in which an unactivated C­(aryl)–N bond is cleaved, leading to the formation of a new C­(aryl)–C bond. The key to the success of this reaction is the utilization of a highly nucleophilic NHC, which enables the formation of a highly nucleophilic ylide intermediate that is generated from an α,β-unsaturated amide.

The nickel-catalyzed cyclization of bisphosphine derivatives to form various phosphacycles is reported. The reaction proceeds via the cleavage of two carbon–phosphorus bonds of the bisphosphine. Unlike the previously reported palladium catalysts, the use of nickel as a catalyst allows for the cyclization that requires C­(alkyl)–P bond cleavage. A phospha-nickelacycle intermediate was successfully isolated and characterized by X-ray crystallography.