88-67-5Relevant articles and documents
Perfluoroalkyl Cobaloximes: Preparation Using Hypervalent Iodine Reagents, Molecular Structures, Thermal and Photochemical Reactivity
Liebing, Phil,Oehler, Florian,Wagner, Mona,Tripet, Pascal F.,Togni, Antonio
, p. 570 - 583 (2018)
Treatment of cobaloximes(II), [Co(Hdmg)2(L)2] (Hdmg = dimethylglyoximate, L = neutral ligand), with perfluoroalkyl iodane reagents leads to the formation of perfluoroalkyl cobaloximes(III), [CoRF(Hdmg)2(L)] (RF = CF3, C2F5, n-C3F7, CF2CF2Ph; L = Py, NH3, MeNH2, PhNH2, MeOH). The synthetic protocol can be significantly simplified to a one-pot procedure starting from cobalt(II) acetate-tetrahydrate. The products have been fully characterized by NMR, IR, and UV/vis spectroscopy as well as single-crystal X-ray diffraction, and the thermal and photochemical reactivity has been studied. According to the Co-L distances in the crystal, the trans influence of the RF- ligands can be rated as C2F5- ≈ n-C3F7- 2CF2Ph- ≈ CF3- 3-. The thermal decomposition of the complexes is different from that of nonfluorinated analogues, probably including perfluoroalkylation of an Hdmg- ligand as the initial step. In the CF3 complexes, the Co-C bond is very resistant against photolysis, but the ligand L is readily exchanged by MeOH upon exposure to blue light. In the complexes with longer RF chains, the Co-C bond is more readily cleaved, and the product distribution depends strongly on the presence of O2. Thus, the alkane RFH is the main product under exclusion of O2, while a fluorinated methyl ester and HF are formed in a methanol solution exposed to air.
Efficiency of lithium cations in hydrolysis reactions of esters in aqueous tetrahydrofuran
Harada, Yumi,Hayashi, Kazuhiko,Ichimaru, Yoshimi,Imai, Masanori,Kojima, Yuki,Maeda, Azusa,Nakayama, Kanae,Sugiura, Kirara
, p. 581 - 594 (2021/06/06)
Lithium cations were observed to accelerate the hydrolysis of esters with hydroxides (KOH, NaOH, LiOH) in a water/tetrahydrofuran (THF) two-phase system. Yields in the hydrolysis of substituted benzoates and aliphatic esters using the various hydroxides were compared, and the effects of the addition of lithium salt were examined. Moreover, it was presumed that a certain amount of LiOH was dissolved in THF by the coordination of THF with lithium cation and hydrolyzed esters even in the THF layer, as in the reaction by a phase-transfer catalyst.
Togni-II Reagent Mediated Selective Hydrotrifluoromethylation and Hydrothiolation of Alkenes?
Teng, Shuang,Meng, Lingkui,Xu, Bingbing,Tu, Guangsheng,Wu, Peng,Liao, Zhiwen,Tan, Yulin,Guo, Jian,Zeng, Jing,Wan, Qian
supporting information, p. 3429 - 3434 (2021/11/08)
Based on the redox reactions of Togni-II reagent and thiols, a thiol-tuned selective functionalization of unactivated olefins was disclosed. In combination with aryl thiols, stoichiometric amount of Togni-II reagent prompted a hydrotrifluoromethylation of alkenes, in which, aryl thiols played as reductant and hydrogen source; while by utilization of alkyl thiols, catalytic amount of Togni-II reagent initiated thiol-ene and thiol-yne reactions. The reported applications are characterized by their operational simplicity and wide functional group tolerance.