Cationic Rhodium(I) Tetrafluoroborate Catalyzed Intramolecular Carbofluorination of Alkenes via Acyl Fluoride C−F Bond Activation**

Abstract

The CÀ F bond of acyl fluorides can be cleaved and added across tethered alkenes in the presence of a cationic rhodium(I) tetrafluoroborate catalyst. This 1,2carbofluorination reaction offers a powerful method for the synthesis of tertiary alkyl fluoride derivatives with an atom economy of 100 %. Mechanistic studies indicate that the concerted action of a rhodium cation and a tetrafluoroborate anion is key for the success of this catalytic cleavage and formation of CÀ F bonds in a controlled manner.

Cooperative Photoredox and N‐Heterocyclic Carbene Catalyzed Fluoroaroylation for the Synthesis of α‐Trifluoromethyl‐Substituted Ketones

“…Selective radical‐radical cross‐coupling will finally deliver the targeted α‐CF 3 ‐substituted ketones through an unprecedented approach (Scheme 1b). Notably, the atom economic use of aroyl fluorides as bifunctional reagents in synthesis is not well established [16e,19–22] …”

“…Notably, the atom economic use of aroyl fluorides as bifunctional reagents in synthesis is not well established. [16e, [19][20][21][22] We commenced the investigations with gem-difluoroalkene 1 a and benzoyl fluoride 2 a as the model substrates. For initial base screening, [Ir(dF(CF 3 )ppy) 2 (5,5'-d(CF 3 )bpy)]PF 6 PC-I (2 mol %) was chosen as the photoredox catalyst in combination with the triazolium salt N1 as the NHC precatalyst (20 mol %).…”

BF3-Catalyzed Intramolecular Fluorocarbamoylation of Alkynes via Halide Recycling

“…Contemporary catalytic platforms have recently emerged to enable the application of highly electrophilic acyl fluorides in atom-economical addition reactions. − The Tobisu group has reported both the inter- and intramolecular fluoroacylation of alkynes via P III/V and Rh I /BF 4 catalysis, respectively. , Studer and co-workers disclosed an intermolecular alkene fluoroacylation reaction of benzofurans and indoles promoted by cooperative N -heterocyclic carbene and photoredox catalysis . In these examples, the high reactivity of acyl fluorides toward nucleophilic substitution was harnessed in the C–F bond cleavage step.…”

BF3-Catalyzed Intramolecular Fluorocarbamoylation of Alkynes via Halide Recycling

“…Contemporary catalytic platforms have recently emerged to enable the application of highly electrophilic acyl fluorides in atom-economical addition reactions. [5][6][7] The Tobisu group has reported both the inter-and intramolecular fluoroacylation of alkynes via P III/IV and Rh I /BF4 catalysis, respectively. 5,6 Studer and co-workers disclosed an intermolecular alkene fluoroacylation reaction of benzofurans and indoles promoted by cooperative NHC and photoredox catalysis.…”

“…[5][6][7] The Tobisu group has reported both the inter-and intramolecular fluoroacylation of alkynes via P III/IV and Rh I /BF4 catalysis, respectively. 5,6 Studer and co-workers disclosed an intermolecular alkene fluoroacylation reaction of benzofurans and indoles promoted by cooperative NHC and photoredox catalysis. 7 In these examples, the high reactivity of acyl fluorides towards nucleophilic substitution was harnessed in the C-F bond cleavage step.…”