- Rapid and column-free syntheses of acyl fluorides and peptides usingex situgenerated thionyl fluoride
-
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.
- Lee, Cayo,Sammis, Glenn M.,Thomson, Brodie J.
-
p. 188 - 194
(2021/12/31)
-
- METHOD AND REAGENT FOR DEOXYFLUORINATION
-
A safe, simple, and selective method and reagent for deoxyfluorination is disclosed. With the method and reagent disclosed herein, organic compounds such as carboxylic acids, carboxylates, carboxylic acid anhydrides, aldehydes, and alcohols can be fluorinated by using the most common nucleophilic fluorinating reagents and electron deficient fluoroarenes as mediators under mild conditions, giving corresponding fluoroorganic compounds in excellent yield with a wide range of functional group compatibility and easy product purification. For example, directly utilizing KF for deoxyfluorination of carboxylic acids provides the most economical and the safest pathway to access acyl fluorides, key intermediates for syntheses of peptide, amide, ester, and dry fluoride salts.
- -
-
Paragraph 0111-0112; 0114-0115; 0134
(2021/05/29)
-
- Deoxyfluorination of Carboxylic, Sulfonic, Phosphinic Acids and Phosphine Oxides by Perfluoroalkyl Ether Carboxylic Acids Featuring CF2O Units
-
The deoxyfluorination of carboxylic, sulfonic, phosphinic acids and phosphine oxides is a fundamentally important approach to access acyl fluorides, sulfonyl fluorides and phosphoric fluorides, thus the development of inexpensive, stable, easy-to-handle, versatile, and efficient deoxyfluorination reagents is highly desired. Herein, we report the use of potassium salts of perfluoroalkyl ether carboxylic acids (PFECA) featuring CF2O units as deoxyfluorination reagents, which are generated mainly as by-products in the manufacture of hexafluoropropene oxide (HFPO). The synthesis of acyl fluorides, sulfonyl fluorides and phosphoric fluorides can be realized via carbonic difluoride (COF2) generated in situ from thermal degradation of the PFECA salt.
- Zhao, Shiyu,Guo, Yong,Su, Zhaoben,Wu, Chengying,Chen, Wei,Chen, Qing-Yun
-
supporting information
p. 1225 - 1232
(2021/05/04)
-
- CsF-Catalyzed Fluoroacylation of Tetrafluoroethylene Using Acyl Fluorides for the Synthesis of Pentafluoroethyl Ketones
-
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
- Ishida, Naoyoshi,Iwamoto, Hiroaki,Sunagawa, Denise Eimi,Ohashi, Masato,Ogoshi, Sensuke
-
supporting information
p. 3137 - 3143
(2020/11/13)
-
- Deoxyfluorination of Carboxylic Acids with KF and Highly Electron-Deficient Fluoroarenes
-
A deoxyfluorination reaction of carboxylic acids using potassium fluoride (KF) and highly electron-deficient fluoroarenes is reported here, giving acyl fluorides in moderate to excellent yield (57-92% based on NMR integration and 34-95% for isolated examples).
- Mao, Siyu,Kramer, Jordan H.,Sun, Haoran
-
p. 6066 - 6074
(2021/05/29)
-
- Synthesis of Acyl Fluorides via DAST-Mediated Fluorinative C-C Bond Cleavage of Activated Ketones
-
A new protocol for preparation of acyl fluorides was developed by recognizing activated ketones as starting materials. The method provides a different scope compared with previously reported methods that employ carboxylic acids as substrates. A working hypothesis of pull-and-push-driven fluorinative C-C bond cleavage was successfully demonstrated by the simple addition of diethylaminosulfur trifluoride (DAST) derivatives to α-oximinoketones. The designed reaction system led to a highly efficient and chemoselective reaction. The wide availability of the ketones allowed for a range of synthetically useful aryloyl and aliphatic acyl fluorides including those containing chiral skeletons. The method is mild, fast, scalable, and potentially one-pot operative.
- Kim, Danhee,Lim, Hee Nam
-
supporting information
p. 7465 - 7469
(2020/10/09)
-
- Synthesis of Arylstannanes via Palladium-Catalyzed Decarbonylative Coupling of Aroyl Fluorides
-
Aryl stannanes are valuable precursors in organic transformations, but their synthetic methods are limited. Here we present a Pd-catalyzed decarbonylative stannylation of acid fluorides in the absence of exogenous base. Various aryl stannanes were efficiently prepared from bench-stable transition metal catalyst and ligand with broad functional group compatibility and substrate scope including natural products and pharmaceuticals. This protocol was also successfully used to a late-stage diversification of an existing uricosuric drug probenecid. (Figure presented.).
- Kayumov, Muzaffar,Zhao, Jian-Nan,Mirzaakhmedov, Sharafitdin,Wang, Dong-Yu,Zhang, Ao
-
supporting information
p. 776 - 781
(2019/11/14)
-
- Methoxylation of Acyl Fluorides with Tris(2,4,6-trimethoxyphenyl)phosphine via C-OMe Bond Cleavage under Metal-Free Conditions
-
Acyl fluorides are subjected to methoxylation with tris(2,4,6-trimethoxyphenyl)phosphine (TMPP) to afford the corresponding methyl esters in good to excellent yields. This transformation is featured by C(sp2)-OMe bond cleavage under metal-free conditions. Unprecedented utilization of TMPP as a methoxylating agent realized the installation of an OMe group into the desired products.
- Ishida, Takumi,Nishihara, Yasushi,Wang, Xiu,Wang, Zhenhua
-
p. 7526 - 7533
(2020/06/27)
-
- Mechanism and Scope of Nickel-Catalyzed Decarbonylative Borylation of Carboxylic Acid Fluorides
-
This Article describes the development of a base-free, nickel-catalyzed decarbonylative coupling of carboxylic acid fluorides with diboron reagents to selectively afford aryl boronate ester products. Detailed studies were conducted to assess the relative rates of direct transmetalation between aryl boronate esters and diboron reagents and a bisphosphine nickel(aryl)(fluoride) intermediate. These investigations revealed that diboron reagents undergo transmetalation with this Ni(aryl)(fluoride) intermediate at rates significantly faster than their aryl boronate ester congeners. Furthermore, the reactivity of both boron reagents toward transmetalation is enhanced with increasing electrophilicity of the boron center. These mechanistic insights were leveraged to develop a catalytic decarbonylative borylation of acid fluorides that proved applicable to a variety of (hetero)aryl carboxylic acid fluorides as well as diverse diboron reagents. The acid fluorides can be generated in situ directly from carboxylic acids. Furthermore, the mechanistic studies directed the identification of various air-stable Ni pre-catalysts for this transformation.
- Malapit, Christian A.,Bour, James R.,Laursen, Simon R.,Sanford, Melanie S.
-
supporting information
p. 17322 - 17330
(2019/11/03)
-
- Base-free nickel-catalysed decarbonylative Suzuki–Miyaura coupling of acid fluorides
-
The Suzuki–Miyaura cross-coupling of organoboron nucleophiles with aryl halide electrophiles is one of the most widely used carbon–carbon bond-forming reactions in organic and medicinal chemistry1,2. A key challenge associated with these transformations is that they generally require the addition of an exogenous base, the role of which is to enable transmetallation between the organoboron nucleophile and the metal catalyst3. This requirement limits the substrate scope of the reaction because the added base promotes competitive decomposition of many organoboron substrates3–5. As such, considerable research has focused on strategies for mitigating base-mediated side reactions6–12. Previous efforts have primarily focused either on designing strategically masked organoboron reagents (to slow base-mediated decomposition)6–8 or on developing highly active palladium precatalysts (to accelerate cross-coupling relative to base-mediated decomposition pathways)10–12. An attractive alternative approach involves identifying combinations of catalyst and electrophile that enable Suzuki–Miyaura-type reactions to proceed without an exogenous base12–14. Here we use this approach to develop a nickel-catalysed coupling of aryl boronic acids with acid fluorides15–17, which are formed in situ from readily available carboxylic acids18–22. This combination of catalyst and electrophile enables a mechanistic manifold in which a ‘transmetallation-active’ aryl nickel fluoride intermediate is generated directly in the catalytic cycle13,16. As such, this transformation does not require an exogenous base and is applicable to a wide range of base-sensitive boronic acids and biologically active carboxylic acids.
- Malapit, Christian A.,Bour, James R.,Brigham, Conor E.,Sanford, Melanie S.
-
p. 100 - 104
(2018/11/25)
-
- Nickel-catalysed decarbonylative borylation of aroyl fluorides
-
The first Ni(cod)2/PPh3 catalyst system has been established for decarbonylative borylation of aroyl fluorides with bis(pinacolato)diboron. A wide range of functional groups in the substrates were well tolerated. The ease of access of the starting aroyl fluorides indicates that these results might become an alternative to the existing decarbonylation events.
- Wang, Zhenhua,Wang, Xiu,Nishihara, Yasushi
-
supporting information
p. 13969 - 13972
(2019/01/03)
-
- Enantioselective acylation of silyl ketene acetals through fluoride anion-binding catalysis
-
A highly enantioselective acylation of silyl ketene acetals with acyl fluorides has been developed to generate useful α,α-disubstituted butyrolactone products. This transformation is promoted by a new thiourea catalyst and 4-pyrrolidinopyridine and represents the first example of enantioselective thiourea anion-binding catalysis with fluoride.
- Birrell, James A.,Desrosiers, Jean-Nicolas,Jacobsen, Eric N.
-
supporting information; experimental part
p. 13872 - 13875
(2011/10/09)
-
- MILD CONVERSION OF PRIMARY ALCOHOLS AND ALDEHYDES TO ACID FLUORIDES WITH CAESIUM FLUOROXYSULPHATE
-
Caesium fluoroxysulphate in acetonitrile medium at 35 deg C converts primary alcohols and alkyl, as well as aryl aldehydes, to acid fluorides in high yield.
- Stavber, Stojan,Planinsek, Zdenka,Zupan, Marko
-
p. 6095 - 6096
(2007/10/02)
-