4855-02-1Relevant articles and documents
New utility of electrophilic trifluoromethylthiolation reagents for the synthesis of a variety of triflones
Huang, Zhongyan,Jia, Shichong,Wang, Chen,Tokunaga, Etsuko,Sumii, Yuji,Shibata, Norio
, p. 61 - 66 (2017)
The synthesis of various triflones has been achieved using electrophilic trifluoromethylthiolation reagents as building blocks, and not as reagents. Trifluoromethanesulfonyl hypervalent iodonium ylide 1a and its diazo-analogue 1b are well-known reagents for electrophilic trifluoromethylthiolation of nucleophiles under copper catalysis. In this paper, we disclose another facet of these reagents as synthetic building blocks of triflones via intramolecular rearrangements. The diazo-compound 1b was converted into amide-, ester- and enol-triflones via the Wolff rearrangement followed by a nucleophilic reaction with aryl- and alkylamines, amino acids, alcohols, and silyl enol ether in heated conditions. On the other hand, the ylide reagent 1a was converted into vinyl triflone via an intramolecular I-O-rearrangement under heat. More interestingly, both 1a and 1b reacted with acetonitrile to give an oxazole-triflone under copper catalysis.
Synthesis of ArCF2X and [18F]Ar-CF3via Cleavage of the Trifluoromethylsulfonyl Group
Yang, Ren-Yin,Gao, Xinyan,Gong, Kehao,Wang, Juan,Zeng, Xiaojun,Wang, Mingwei,Han, Junbin,Xu, Bo
supporting information, p. 164 - 168 (2021/12/17)
A versatile synthesis of ArCF2X and [18F]Ar-CF3 type compounds from readily available ArCF2SO2CF3 has been developed. Diverse nucleophiles, including weak nucleophiles such as halides (18F-, Cl-, Br-, and I-), RSH, and ROH, could react with ArCF2SO2CF3 efficiently to give the corresponding difluoromethylene products. The control experiments and the Hammett plot indicated that the reaction might proceed through a difluorocarbocation intermediate generated from the steric hindrance-assisted cleavage of the trifluoromethylsulfonyl group.
Chemo-, regio- And stereoselective synthesis of monofluoroalkenes via a tandem fluorination-desulfonation sequence
Xu, Bo,Yang, Ren-Yin
supporting information, p. 7802 - 7805 (2021/08/13)
A widely applicable approach for the synthesis of Z-monofluoroalkenes from readily available alkyl triflones and NFSI has been reported. The reaction proceeded under mild conditions, affording mono-fluorinated alkenes in good to excellent yields with exce
One-Pot Substitution of Aliphatic Alcohols Mediated by Sulfuryl Fluoride
Dubois, Rudy,Epifanov, Maxim,Hodgson, Jack W.,Mo, Jia Yi,Sammis, Glenn M.
supporting information, p. 4958 - 4962 (2020/04/22)
The Mitsunobu reaction is a powerful transformation for the one-pot activation and substitution of aliphatic alcohols. Significant efforts have focused on modifying the classic conditions to overcome problems associated with purification from phosphine-based byproducts. Herein, we report a phosphine free method for alcohol activation and substitution that is mediated by sulfuryl fluoride. This new method is effective for a wide range of primary alcohols using phthalimide, di-tert-butyl-iminodicarboxylate, and aromatic thiol nucleophiles in 74 % average yield. Activated carbon nucleophiles and a deactivated phenol were also effective for this reaction in good yields. Secondary alcohols were also successful substrates using aryl thiols, affording the corresponding sulfides in 56 % average yield with enantiomeric ratios up to 99:1. This new protocol has a distinct synthetic advantage over many existing phosphine-based methods as the byproducts are readily separable. This feature was exploited in several examples that did not require chromatography for purification. Furthermore, the mild reaction conditions enabled further in situ derivatization for the one-pot conversion of alcohols to amines or sulfones. This method also provides a boarder nucleophile scope compared to existing phosphine-free methods.
