560-02-1Relevant academic research and scientific papers
Photocatalytic amidation and esterification with perfluoroalkyl iodide
Xiao, Yelan,Chun, Yuen-Kiu,Cheng, Shun-Cheung,Ng, Chi-On,Tse, Man-Kit,Lei, Ngai-Yu,Liu, Ruoyang,Ko, Chi-Chiu
, p. 556 - 562 (2021/02/09)
The successful generation of perfluoroalkyl radicals (Rf˙) through photoredox catalysis has inspired us to investigate the preparation of various organofluorine species. In this work, visible light-induced photocatalytic reactions for the preparation of perfluoroalkyl amides and esters from the corresponding amines and alcohols using different types of triplet emitters as photocatalysts have been studied. The effects of the excited-state characteristics and redox potentials of the photocatalysts have been elucidated. Under optimized reaction conditions, these reactions can be performed successfully with different types of amines or alcohols and perfluoroalkyl iodides. Detailed mechanistic studies based on emission quenching experiments have been performed to study the photocatalytic cycles as well as the role of the different reagents. The proposed mechanism has also been examined by DFT calculations.
Hexamethyldisilazane as an acylation generator for perfluorocarboxylic acids in quantitative derivatization of primary phenylalkyl amines confirmed by GC/MS and computations
Molnr, Borbla,Csmpai, Antal,Molnr-Perl, Ibolya
, p. 848 - 852 (2015/02/19)
A novel, selective acylation of primary phenylalkyl amines (PPAAs) using hexamethyldisilazane (HMDS) and perfluorocarboxylic acids (PFCAs) is noted. Couples, like HMDS and trifluoroacetic acid, HMDS and pentafluoropropionic acid, or HMDS and heptafluorobutyric acid trigger PPAAs' quantitative acylation. Processes' selectivity was characterized by applying all couples to derivatize benzyl, 2-phenylethyl, 3-phenylpropyl, 4-phenylbutyl amines, and their relevant substituted versions. Aliphatic amines were unreactive. Identification, quantification, proportionality, and stoichiometry in derivatization processes were determined by gas chromatography/mass spectrometry. Reaction conditions were optimized depending on reagents' molar ratios, solvents, and temperatures applied. The new acylation method, in comparison to the traditional ones, obtained with trifluoroacetic anhydride, heptafluorobutyric anhydride, and N-methyl-bis(trifluoroacetamide), offers numerous advantages. Derivatives, provided by couples, can be directly injected onto the column, avoiding loss of species, saving time, work, and cost in the preparation process. Due to traditional reagents' excess evaporation by nitrogen drying, the loss of trifluoroacylated species proved to be 65% or less. Regarding heptafluorobutyryl species, their losses varied between 25% and 5%. Unified huge responses, obtained with the HMDS and PFCA couples are attributable to their direct injection onto the column and to fragments sourced from the molecular ions and from their self-chemical ionization ([M]?+, [M+147]+, i.e., [M+(CH3)2-Si=O-Si-(CH3)3]+). The reaction mechanism, due to the HMDS symmetrical structure, acting HMDS as acylation generator for PFCAs, was confirmed by density functional theory (DFT) computation.
Biomimetic reductive amination of perfluoroalkylcarboxylic acids to α,α-dihydroperfluoroalkylamines
Soloshonok, Vadim A,Ohkura, Hironari,Uneyama, Kenji
, p. 5449 - 5452 (2007/10/03)
The first general method for the reducing reagent-free, biomimetic transformation of perfluorocarboxylic acids to the α,α-dihydroperfluoroalkyl amines is reported. High chemical yields and simplicity of the experimental procedure render this method immediately useful and synthetically superior to the conventional approaches relying on application of reducing reagents.
