- Synthesis and Reactivity of Fluoroalkyl Copper Complexes by the Oxycupration of Tetrafluoroethylene
-
The copper(I)-mediated generation of -OCF2CF2- moieties by the oxycupration of tetrafluoroethylene (TFE) using either copper aryloxides or alkoxides is disclosed. The key intermediates, 2-aryloxy-1,1,2,2-tetrafluoroethyl and 2-alkoxy
- Ohashi, Masato,Adachi, Takuya,Ishida, Naoyoshi,Kikushima, Kotaro,Ogoshi, Sensuke
-
-
Read Online
- Binuclear β-diketiminate complexes of copper(i)
-
The reaction of a series of dinucleating bis(β-diketiminate) pro-ligands with mesitylcopper in the presence and absence of mono and diphosphines has allowed the isolation of a new series of dicopper(i) complexes. Inclusion of trans-1,2-cyclohexyl (1), 2,6-pyridyl (2), and 2,2′-oxydiaryl (3) spacers between the β-diketiminate units has been studied. The isolation of three new copper(i) phosphine complexes [1·Cu2(PPh3)2], [2·Cu2(PPh3)2] and [3·Cu2(PPh3)2] is reported. While these compounds display large Cu?Cu separations of 5.4-7.9 ? in the solid state, solution data are consistent with a large degree of conformational freedom. Modification of the monophosphine to a diphosphine, DPPE, allowed the isolation of the novel 11-membered bimetallic macrocycle [2·Cu2(DPPE)] containing both a binucleating nitrogen based ligand and a chelating diphosphine. While acetonitrile adducts of this series could also be generated in situ, under forcing conditions reaction of the 2,6-pyridyl bridged ligand with mesityl copper led to the formation [2·Cu2]2. This latter complex is a dimer of dicopper(i) units in which the bis(β-diketiminate) ligand now binds four copper(i) centers through not only the expected κ2-N,N′-chelation but also κ1- and η2-binding of the central pyridine through orthogonal Cu-N and Cu-arene interactions. Reversible coordination of alkenes, pyridine and quinoline to the copper cluster was identified allowing the isolation and structural characterisation of a further series of dinuclear complexes [2·Cu2(pyridine)2], [2·Cu2(cyclopentene)2] and [2·Cu2(norbornene)2]. Solution studies allow quantification of the reversible binding event through a van't Hoff analysis. Both solution and the solid state data suggest a weak anagostic interaction exists in the latter two alkene complexes of copper(i). The new complexes have been characterized by X-ray diffraction, multinuclear NMR spectroscopy and CHN analysis.
- Phanopoulos, Andreas,Leung, Alice H. M.,Yow, Shuhui,Palomas, David,White, Andrew J. P.,Hellgardt, Klaus,Horton, Andrew,Crimmin, Mark R.
-
supporting information
p. 2081 - 2090
(2017/02/23)
-
- Enantioselective Borylative Dearomatization of Indoles through Copper(I) Catalysis
-
The enantioselective borylative dearomatization of a heteroaromatic compound has been achieved using a copper(I) catalyst and a diboron reagent. This reaction involves the regio- and enantioselective addition of active borylcopper(I) species to indole-2-carboxylates, followed by the diastereoselective protonation of the resulting copper(I) enolate to give the corresponding chiral indolines, which bear consecutive stereogenic centers.
- Kubota, Koji,Hayama, Keiichi,Iwamoto, Hiroaki,Ito, Hajime
-
supporting information
p. 8809 - 8813
(2015/11/27)
-
- Porphyrinylboranes Synthesized via Porphyrinyllithiums
-
As the most nucleophilic porphyrins, meso- or β-lithiated porphyrins were generated by iodine-lithium exchange reactions of the corresponding iodoporphyrins with n-butyllithium at -98°C. Porphyrinyllithiums thus prepared were used for synthesis of dimesitylporphyrinylboranes through reactions with fluorodimesitylborane. The boryl groups proved to serve as an electron-accepting unit to alter the photophysical and electrochemical properties. In addition, 5-diarylamino-15-dimesitylboryl-substituted donor-accepter porphyrins showed increased intramolecular charge-transfer character in the S1 state. Furthermore, the reaction of β-lithiated porphyrin with dichloromesitylborane provided a boron-bridged porphyrin dimer, which exhibited a conjugative interaction between two porphyrin units through the vacant p-orbital on the boron center. Porphyrinyllithiums were generated by iodine-lithium exchange of the corresponding iodoporphyrins. The porphyrinyllithiums were useful for the synthesis of a series of porphyrinylboranes through reactions with suitable haloboranes. The boryl groups served as electron-accepting units to alter the photophysical and electrochemical properties. A B,N-substituted donor-accepter porphyrin showed an increased intramolecular charge-transfer character in the S1 state. A boron-bridged porphyrin dimer exhibited a conjugative interaction between two porphyrin units through the vacant p-orbital at the boron atom.
- Fujimoto, Keisuke,Yorimitsu, Hideki,Osuka, Atsuhiro
-
supporting information
p. 11311 - 11314
(2015/08/03)
-
- Isolation and X-ray crystal structures of triarylphosphine radical cations
-
Salts containing triarylphosphine radical cations 1?+ and 2?+ have been isolated and characterized by electron paramagnetic resonance (EPR) and UV-vis absorption spectroscopy as well as single-crystal X-ray diffraction. Radical 1?+ exhibits a relaxed pyramidal geometry, while radical 2?+ becomes fully planar. EPR studies and theoretical calculations showed that the introduction of bulky aryl groups leads to enhanced p character of the singly occupied molecular orbital, and the radicals become less pyramidalized or fully flattened.
- Pan, Xiaobo,Chen, Xiaoyu,Li, Tao,Li, Yizhi,Wang, Xinping
-
supporting information
p. 3414 - 3417
(2013/04/23)
-