@article{FoehrenbacherKrahfussZapfetal.2021,
  author    = {F{\"o}hrenbacher, Steffen A. and Krahfuss, Mirjam J. and Zapf, Ludwig and Friedrich, Alexandra and Ignat'ev, Nikolai V. and Finze, Maik and Radius, Udo},
  title     = {Tris(pentafluoroethyl)difluorophosphorane: a versatile fluoride acceptor for transition metal chemistry},
  series = {Chemistry Europe},
  volume    = {27},
  journal   = {Chemistry Europe},
  number    = {10},
  doi       = {10.1002/chem.202004885},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256665},
  pages     = {3504-3516},
  year      = {2021},
  abstract  = {Fluoride abstraction from different types of transition metal fluoride complexes [L\(_n\)MF] (M=Ti, Ni, Cu) by the Lewis acid tris(pentafluoroethyl)difluorophosphorane (C\(_2\)F\(_5\))\(_3\)PF\(_2\) to yield cationic transition metal complexes with the tris(pentafluoroethyl)trifluorophosphate counterion (FAP anion, [(C\(_2\)F\(_5\))\(_3\)PF\(_3\)]\(^-\)) is reported. (C\(_2\)F\(_5\))\(_3\)PF\(_2\) reacted with trans-[Ni(iPr\(_2\)Im)\(_2\)(Ar\(^F\))F] (iPr2Im=1,3-diisopropylimidazolin-2-ylidene; Ar\(^F\)=C\(_6\)F\(_5\), 1 a; 4-CF\(_3\)-C\(_6\)F\(_4\), 1 b; 4-C\(_6\)F\(_5\)-C\(_6\)F\(_4\), 1 c) through fluoride transfer to form the complex salts trans-[Ni(iPr\(_2\)Im)\(_2\)(solv)(Ar\(^F\))]FAP (2 a-c[solv]; solv=Et\(_2\)O, CH\(_2\)Cl\(_2\), THF) depending on the reaction medium. In the presence of stronger Lewis bases such as carbenes or PPh\(_3\), solvent coordination was suppressed and the complexes trans-[Ni(iPr\(_2\)Im)\(_2\)(PPh\(_3\))(C\(_6\)F\(_5\))]FAP (trans-2 a[PPh\(_3\)]) and cis-[Ni(iPr\(_2\)Im)\(_2\)(Dipp\(_2\)Im)(C\(_6\)F\(_5\))]FAP (cis-2 a[Dipp\(_2\)Im]) (Dipp\(_2\)Im=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) were isolated. Fluoride abstraction from [(Dipp\(_2\)Im)CuF] (3) in CH\(_2\)Cl\(_2\) or 1,2-difluorobenzene led to the isolation of [{(Dipp\(_2\)Im)Cu}\(_2\)]\(^2\)\(^+\)2 FAP\(^-\) (4). Subsequent reaction of 4 with PPh\(_3\) and different carbenes resulted in the complexes [(Dipp\(_2\)Im)Cu(LB)]FAP (5 a-e, LB=Lewis base). In the presence of C6Me6, fluoride transfer afforded [(Dipp\(_2\)Im)Cu(C\(_6\)Me\(_6\))]FAP (5 f), which serves as a source of [(Dipp\(_2\)Im)Cu)]\(^+\). Fluoride abstraction of [Cp\(_2\)TiF\(_2\)] (7) resulted in the formation of dinuclear [FCp\(_2\)Ti(μ-F)TiCp\(_2\)F]FAP (8) (Cp=η\(^5\)-C\(_5\)H\(_5\)) with one terminal fluoride ligand at each titanium atom and an additional bridging fluoride ligand.},
  language  = {en}
}
@article{LorkowskiKrahfussKubickietal.2019,
  author    = {Lorkowski, Jan and Krahfuß, Mirjam and Kubicki, Maciej and Radius, Udo and Pietraszuk, Cezary},
  title     = {Intramolecular Ring-Expansion Reaction (RER) and Intermolecular Coordination of In Situ Generated Cyclic (Amino)(aryl)carbenes (cAArCs)},
  series = {Chemistry - A European Journal},
  volume    = {25},
  journal   = {Chemistry - A European Journal},
  number    = {48},
  doi       = {10.1002/chem.201902630},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-212496},
  pages     = {11365 -- 11374},
  year      = {2019},
  abstract  = {Cyclic (amino)(aryl)carbenes (cAArCs) based on the isoindoline core were successfully generated in situ by α-elimination of 3-alkoxyisoindolines at high temperatures or by deprotonation of isoindol-2-ium chlorides with sodium or copper(I) acetates at low temperatures. 3-Alkoxy-isoindolines 2 a,b-OR (R=Me, Et, iPr) have been prepared in high yields by the addition of a solution of 2-aryl-1,1-diphenylisoindol-2-ium triflate (1 a,b-OTf; a: aryl=Dipp=2,6-diisopropylphenyl; b: Mesityl-, Mes=2,4,6-trimethylphenyl) to the corresponding alcohol (ROH) with NEt3 at room temperature. Furthermore, the reaction of 2 a,b-OMe in diethyl ether with a tenfold excess of hydrochloric acid led to the isolation of the isoindol-2-ium chlorides 1 a,b-Cl in high yields. The thermally generated cAArC reacts with sulfur to form the thioamide 3 a. Without any additional trapping reagent, in situ generation of 1,1-diphenylisoidolin-3-ylidenes does not lead to the isolation of these compounds, but to the reaction products of the insertion of the carbene carbon atom into an ortho C-H bond of a phenyl substituent, followed by ring-expansion reaction; namely, anthracene derivatives 9-N(H)aryl-10-Ph-C14H8 4 a,b (a: Dipp; b: Mes). These compounds are conveniently synthesized by deprotonation of the isoindol-2-ium chlorides with sodium acetate in high yields. Deprotonation of 1 a-Cl with copper(I) acetate at low temperatures afforded a mixture of 4 a and the corresponding cAArC copper(I) chloride 5 a, and allowed the isolation and structural characterization of the first example of a cAArC copper complex of general formula [(cAArC)CuCl].},
  language  = {en}
}
@article{LorkowskiKrahfussKubickietal.2019,
  author    = {Lorkowski, Jan and Krahfuss, Mirjam and Kubicki, Maciej and Radius, Udo and Pietraszuk, Cezary},
  title     = {Intramolecular ring expansion reaction (RER) and intermolecular coordination of in situ generated Cyclic (Amino)(Aryl)Carbenes (cAArCs)},
  series = {Chemistry - A European Journal},
  volume    = {25},
  journal   = {Chemistry - A European Journal},
  number    = {48},
  doi       = {10.1002/chem.201902630},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204847},
  pages     = {11365-11374},
  year      = {2019},
  abstract  = {Cyclic (amino)(aryl)carbenes (cAArCs) based on the isoindoline core were successfully generated in situ by α-elimination of 3-alkoxyisoindolines at high temperatures or by deprotonation of isoindol-2-ium chlorides with sodium or copper(I) acetates at low temperatures. 3-Alkoxy-isoindolines 2 a ,b-OR (R=Me, Et, i Pr) have been prepared in high yields by the addition of a solution of 2-aryl-1,1-diphenylisoindol-2-ium triflate (1 a ,b-OTf ; a : aryl=Dipp=2,6-diisopropylphenyl; b : Mesityl-, Mes=2,4,6-trimethylphenyl) to the corresponding alcohol (ROH) with NEt3 at room temperature. Furthermore, the reaction of 2 a ,b-OMe in diethyl ether with a tenfold excess of hydrochloric acid led to the isolation of the isoindol-2-ium chlorides 1 a ,b-Cl in high yields. The thermally generated cAArC reacts with sulfur to form the thioamide 3 a . Without any additional trapping reagent, in situ generation of 1,1-diphenylisoidolin-3-ylidenes does not lead to the isolation of these compounds, but to the reaction products of the insertion of the carbene carbon atom into an ortho C-H bond of a phenyl substituent, followed by ring-expansion reaction; namely, anthracene derivatives 9-N(H)aryl-10-Ph-C14H8 4 a ,b (a : Dipp; b : Mes). These compounds are conveniently synthesized by deprotonation of the isoindol-2-ium chlorides with sodium acetate in high yields. Deprotonation of 1 a-Cl with copper(I) acetate at low temperatures afforded a mixture of 4 a and the corresponding cAArC copper(I) chloride 5 a , and allowed the isolation and structural characterization of the first example of a cAArC copper complex of general formula [(cAArC)CuCl].},
  language  = {en}
}