1711-06-4Relevant articles and documents
Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
supporting information, p. 5022 - 5037 (2021/05/04)
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
supporting information, p. 17887 - 17896 (2020/08/19)
An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.
Formamide catalyzed activation of carboxylic acids-versatile and cost-efficient amidation and esterification
Huy, Peter H.,Mbouhom, Christelle
, p. 7399 - 7406 (2019/08/20)
A novel, broadly applicable method for amide C-N and ester C-O bond formation is presented based on formylpyrrolidine (FPyr) as a Lewis base catalyst. Herein, trichlorotriazine (TCT), which is the most cost-efficient reagent for OH-group activation, was employed in amounts of ≤40 mol% with respect to the starting material (100 mol%). The new approach is distinguished by excellent cost-efficiency, waste-balance (E-factor down to 3) and scalability (up to >80 g). Moreover, high levels of functional group compatibility, which includes acid-labile acetals and silyl ethers, are demonstrated and even peptide C-N bonds can be formed. In comparison to reported amidation procedures using TCT, yields are considerably improved (for instance from 26 to 91%) and esterification is facilitated for the first time in synthetically useful yields. These significant enhancements are rationalized by activation by means of acid chlorides instead of less electrophilic acid anhydride intermediates.
Functional Group Transposition: A Palladium-Catalyzed Metathesis of Ar-X σ-Bonds and Acid Chloride Synthesis
De La Higuera Macias, Maximiliano,Arndtsen, Bruce A.
supporting information, p. 10140 - 10144 (2018/08/23)
We describe the development of a new method to use palladium catalysis to form functionalized aromatics: via the metathesis of covalent σ-bonds between Ar-X fragments. This transformation demonstrates the dynamic nature of palladium-based oxidative addition/reductive elimination and offers a straightforward approach to incorporate reactive functional groups into aryl halides through exchange reactions. The reaction has been exploited to assemble acid chlorides without the use of high energy halogenating or toxic reagents and, instead, via the metathesis of aryl iodides with other acid chlorides.
Method of co-producing methyl benzoic acid, methylbenzoyl chloride and phthaloyl dichloride
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Paragraph 18-24; 27; 28, (2018/06/16)
The invention discloses a method of co-producing methyl benzoic acid, methylbenzoyl chloride and phthaloyl dichloride. The method comprises the following steps: (1) continuously introducing xylene, acatalyst and oxygen-containing gas into an oxidizing reactor to react to obtain an oxidized reaction solution; (2) rectifying and separating the oxidized reaction solution to obtain a low-boiling-point component and an initial evaporative tower bottom; (3) rectifying the initial evaporative tower bottom to obtain a methyl benzoic acid product and a tower bottom; (4) carrying out an acylating chlorination reaction on the tower bottom and an acylating chlorination reagent to obtain an acyl chloride reaction solution; and (5) rectifying and separating the acyl chloride reaction solution to separately obtain methylbenzoyl chloride and phthaloyl dichloride products. The method provided by the invention has the advantages of being simple in process, small in equipment investment, green and environment-friendly and good in comprehensive economical benefit.
Anhydrides from aldehydes or alcohols via oxidative cross-coupling
Gaspa, Silvia,Amura, Ida,Porcheddu, Andrea,De Luca, Lidia
supporting information, p. 931 - 939 (2017/02/10)
A novel type of metal-free oxidative cross-coupling for the synthesis of symmetrical and mixed anhydrides from aldehydes or benzylic alcohols has been developed. The aldehydes or alcohols were converted in situ into their corresponding acyl chlorides, which were then reacted with an array of carboxylic acids. The methodology has a general applicability, and was successfully employed to prepare either aromatic or aliphatic symmetrical anhydrides and mixed anhydrides, which are very unstable compounds.
Metal-free oxidative self-coupling of aldehydes or alcohols to symmetric carboxylic anhydrides
Gaspa, Silvia,Porcheddu, Andrea,De Luca, Lidia
supporting information, p. 2533 - 2536 (2017/06/13)
A metal-free synthesis of symmetrical anhydrides has been developed starting from aldehydes, both aliphatic and aromatic or primary benzylic alcohols. The reaction occurs at room temperature and makes use of trichloroisocyanuric acid (TCCA) as an oxidant providing the desired carboxylic anhydrides in satisfactory yields.
A General Cp*CoIII-Catalyzed Intramolecular C?H Activation Approach for the Efficient Total Syntheses of Aromathecin, Protoberberine, and Tylophora Alkaloids
Lerchen, Andreas,Knecht, Tobias,Koy, Maximilian,Daniliuc, Constantin G.,Glorius, Frank
supporting information, p. 12149 - 12152 (2017/09/13)
Herein, we report a Cp*CoIII-catalyzed C?H activation approach as the key step to create highly valuable isoquinolones and pyridones as building blocks that can readily be applied in the total syntheses of a variety of aromathecin, protoberberine, and tylophora alkaloids. This particular C?H activation/annulation reaction was achieved with several terminal as well as internal alkyne coupling partners delivering a broad scope with excellent functional group tolerance. The synthetic applicability of this protocol reported herein was demonstrated in the total syntheses of two Topo-I-Inhibitors and two 8-oxyprotoberberine cores that can be further elaborated into the tetrahydroprotoberberine and the protoberberine alkaloid core. Moreover these building blocks were also transformed to six different tylophora alkaloids in expedient fashion.
A O-between the - trifluoromethyl benzoic acid to synthetic method (by machine translation)
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Paragraph 0028, (2017/12/29)
The present invention provides a O-between the - trifluoromethyl benzoic acid to the synthesis method, the method comprises the following steps: (1) between adjacent to methyl benzoic acid acylated preparation between neighbour methyl benzoyl chloride; (2) between the adjacent methyl benzoyl chloride to chlorine light between neighbour trichloromethyl benzoyl chloride is obtained; (3) adjacent to the trichloromethyl benzoyl chloride fluoride obtained between between neighbour trifluoromethyl methyl benzoyle fluoride; (4) adjacent to the trifluoromethyl benzoyle fluoride hydrolysis between the final product is obtained between neighbour trifluoromethyl methyl benzoic acid. The method of the invention cheap raw material, the product yield is high, the process is simple, is favorable for industrial production. (by machine translation)
Synthesis method of o-trifluoromethyl methyl benzoate, m-trifluoromethyl methyl benzoate and p-trifluoromethyl methyl benzoate
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Paragraph 0016, (2018/03/01)
The invention provides a synthesis method of o-trifluoromethyl methyl benzoate, m-trifluoromethyl methyl benzoate and p-trifluoromethyl methyl benzoate. The synthesis method comprises the following steps: taking methyl benzoic acid as a raw material, carrying out acylating chlorination to obtain methylbenzoyl chloride, carrying out side-chain chlorination to obtain trichloromethyl benzoyl chloride, carrying out fluorination substitution to obtain trifluoromethyl benzoyl fluoride, and carrying out esterification to obtain a final product which is trifluoromethyl methyl benzoate. The synthesis method can be used for producing the o-trifluoromethyl methyl benzoate, the m-trifluoromethyl methyl benzoate and the p-trifluoromethyl methyl benzoate, is easily available in raw material, mild in reaction mechanism, high in reaction yield, few in reaction by-products, low in yield of three wastes and easy in treatment of three wastes, and is suitable for industrial production.
