458-69-5Relevant academic research and scientific papers
Rapid and column-free syntheses of acyl fluorides and peptides usingex situgenerated thionyl fluoride
Lee, Cayo,Sammis, Glenn M.,Thomson, Brodie J.
, p. 188 - 194 (2021/12/31)
Thionyl fluoride (SOF2) was first isolated in 1896, but there have been less than 10 subsequent reports of its use as a reagent for organic synthesis. This is partly due to a lack of facile, lab-scale methods for its generation. Herein we report a novel protocol for theex situgeneration of SOF2and subsequent demonstration of its ability to access both aliphatic and aromatic acyl fluorides in 55-98% isolated yields under mild conditions and short reaction times. We further demonstrate its aptitude in amino acid couplings, with a one-pot, column-free strategy that affords the corresponding dipeptides in 65-97% isolated yields with minimal to no epimerization. The broad scope allows for a wide range of protecting groups and both natural and unnatural amino acids. Finally, we demonstrated that this new method can be used in sequential liquid phase peptide synthesis (LPPS) to afford tri-, tetra-, penta-, and decapeptides in 14-88% yields without the need for column chromatography. We also demonstrated that this new method is amenable to solid phase peptide synthesis (SPPS), affording di- and pentapeptides in 80-98% yields.
CsF-Catalyzed Fluoroacylation of Tetrafluoroethylene Using Acyl Fluorides for the Synthesis of Pentafluoroethyl Ketones
Ishida, Naoyoshi,Iwamoto, Hiroaki,Sunagawa, Denise Eimi,Ohashi, Masato,Ogoshi, Sensuke
supporting information, p. 3137 - 3143 (2020/11/13)
A catalytic method for the synthesis of pentafluoroethyl ketones has been developed. The cesium fluoride catalyst can be used to convert acyl fluorides into the pentafluoroethyl ketones under tetrafluoroethylene pressure without generating stoichiometric
Metal-free approach for hindered amide-bond formation with hypervalent iodine(iii) reagents: application to hindered peptide synthesis
Lee, Hyo-Jun,Huang, Xiao,Sakaki, Shigeyoshi,Maruoka, Keiji
, p. 848 - 855 (2021/02/09)
A new bio-inspired approach is reported for amide and peptide synthesis using α-amino esters that possess a potential activating group (PAG) at the ester residue. To activate the ester functionality under mild metal-free conditions, we exploited the facile dearomatization of phenols with hypervalent iodine(iii) reagents. Using a pyridine-hydrogen fluoride complex, highly reactive acyl fluoride intermediates can be successfully generated, thereby allowing for the smooth formation of sterically hindered amides and peptides from bulky amines and α-amino esters, respectively.
Rh-Catalyzed General Method for Directed C-H Functionalization via Decarbonylation of in-Situ-Generated Acid Fluorides from Carboxylic Acids
He, Bangyue,Liu, Xiaojie,Li, Hongyi,Zhang, Xiaofeng,Ren, Yuxi,Su, Weiping
supporting information, p. 4191 - 4196 (2021/05/26)
A Rh-catalyzed decarbonylative C-H coupling of in-situ-generated acid fluorides with amide substrates bearing ortho-Csp2-H bonds has been developed. This method enables alkyl, aryl, and alkenyl carboxylic acids to undergo decarbonylative coupling with C-H bonds of (hetero)aromatic or alkenyl amides in generally good yields via the in situ conversion of carboxylic acids into acid fluorides and also allows for the functionalization of a series of structurally complex carboxyl-containing natural products and pharmaceuticals as well as pharmaceutical amide derivatives.
Acyl fluorides as direct precursors to fluoride ketyl radicals: Reductive deuteration using SmI2and D2O
Li, Hengzhao,Peng, Mengqi,Lai, Zemin,Ning, Lei,Chen, Xingyue,Zhang, Xiaoxu,Wang, Pengjie,Szostak, Roman,Szostak, Michal,An, Jie
supporting information, p. 5195 - 5198 (2021/05/31)
A highly chemoselective reductive deuteration of acyl fluorides to provide α,α-dideuterio alcohols with exquisite levels of deuterium incorporation was developed using SmI2 and D2O as the deuterium source. This method introduces acyl fluorides as attracti
Radical-Mediated Activation of Esters with a Copper/Selectfluor System: Synthesis of Bulky Amides and Peptides
Matsumoto, Akira,Wang, Zhe,Maruoka, Keiji
, p. 5401 - 5411 (2021/04/12)
Herein, we describe a new approach for the activation of esters via a radical-mediated process enabled by a copper/Selectfluor system. A variety of para-methoxybenzyl esters derived from bulky carboxylic acids and amino acids can be easily converted into the corresponding acyl fluorides, directly used in the one-pot synthesis of amides and peptides. As a proof of concept, this method was applied to the iterative formation of sterically hindered amide bonds.
Gram-Scale Preparation of Acyl Fluorides and Their Reactions with Hindered Nucleophiles
Barbasiewicz, Micha?,Tryniszewski, Micha?
, (2021/11/30)
A series of acyl fluorides was synthesized at 100 mmol scale using phase-transfer-catalyzed halogen exchange between acyl chlorides and aqueous bifluoride solution. The convenient procedure consists of vigorous stirring of the biphasic mixture at room temperature, followed by extraction and distillation. Isolated acyl fluorides (usually 7-20 g) display excellent purity and can be transformed into sterically hindered amides and esters when treated with lithium amide bases and alkoxides under mild conditions.
Direct amidation of acid fluorides using germanium amides
Hayatifar, Ardalan,Elifritz, Emily A.,Bloom, Molly B.,Pixley, Kaitlyn M.,Fennell, Christopher J.,Weinert, Charles S.
supporting information, p. 4490 - 4493 (2021/04/12)
Amide functional groups are an essential linkage that are found in peptides, proteins, and pharmaceuticals and new methods are constantly being sought for their formation. Here, a new method for their preparation is presented where germanium amides Ph3GeNR2convert acid fluorides directly to amides. These germanium amides serve to abstract the fluorine atom of the acid fluoride and transfer their amide group -NR2to the carbonyl carbon, and so function as amidation reagents.
N-Hydroxybenzimidazole as a structurally modifiable platform forN-oxyl radicals for direct C-H functionalization reactions
Hatanaka, Miho,Jiang, Julong,Maruoka, Keiji,Matsumoto, Akira,Sakamoto, Ryu,Sakurai, Shunya,Tsuzuki, Saori,Yoshii, Tomomi
, p. 5772 - 5778 (2020/06/22)
Methods for direct functionalization of C-H bonds mediated byN-oxyl radicals constitute a powerful tool in modern organic synthesis. While severalN-oxyl radicals have been developed to date, the lack of structural diversity for these species has hampered further progress in this field. Here we designed a novel class ofN-oxyl radicals based onN-hydroxybenzimidazole, and applied them to the direct C-H functionalization reactions. The flexibly modifiable features of these structures enabled facile tuning of their catalytic performance. Moreover, with these organoradicals, we have developed a metal-free approach for the synthesis of acyl fluoridesviadirect C-H fluorination of aldehydes under mild conditions.
Halide-Accelerated Acyl Fluoride Formation Using Sulfuryl Fluoride
Foth, Paul J.,Malig, Thomas C.,Yu, Hao,Bolduc, Trevor G.,Hein, Jason E.,Sammis, Glenn M.
supporting information, p. 6682 - 6686 (2020/09/02)
Herein, we report a new one-pot sequential method for SO2F2-mediated nucleophilic acyl substitution reactions starting from carboxylic acids. A mechanistic study revealed that SO2F2-mediated acid activation proceeds via the anhydride, which is then converted to the corresponding acyl fluoride. Tetrabutylammonium chloride or bromide accelerate the formation of acyl fluoride. Optimized halide-accelerated conditions were used to synthesize acyl fluorides in 30-80percent yields, and esters, amides, and thioesters in 72-96percent yields without reoptimization for each nucleophile.
