6757-31-9Relevant articles and documents
Nitrogen Atom Transfer Catalysis by Metallonitrene C?H Insertion: Photocatalytic Amidation of Aldehydes
Schmidt-R?ntsch, Till,Verplancke, Hendrik,Lienert, Jonas N.,Demeshko, Serhiy,Otte, Matthias,Van Trieste, Gerard P.,Reid, Kaleb A.,Reibenspies, Joseph H.,Powers, David C.,Holthausen, Max C.,Schneider, Sven
, (2022/01/20)
C?H amination and amidation by catalytic nitrene transfer are well-established and typically proceed via electrophilic attack of nitrenoid intermediates. In contrast, the insertion of (formal) terminal nitride ligands into C?H bonds is much less developed and catalytic nitrogen atom transfer remains unknown. We here report the synthesis of a formal terminal nitride complex of palladium. Photocrystallographic, magnetic, and computational characterization support the assignment as an authentic metallonitrene (Pd?N) with a diradical nitrogen ligand that is singly bonded to PdII. Despite the subvalent nitrene character, selective C?H insertion with aldehydes follows nucleophilic selectivity. Transamidation of the benzamide product is enabled by reaction with N3SiMe3. Based on these results, a photocatalytic protocol for aldehyde C?H trimethylsilylamidation was developed that exhibits inverted, nucleophilic selectivity as compared to typical nitrene transfer catalysis. This first example of catalytic C?H nitrogen atom transfer offers facile access to primary amides after deprotection.
Method for preparing methyl 4-cyanobenzoate and method for preparing 4-cyanobenzoic acid
-
, (2021/06/09)
The invention relates to the field of synthesis, and discloses a method for preparing methyl 4-cyanobenzoate and a method for preparing 4-cyanobenzoic acid. The method for preparing methyl 4-cyanobenzoate comprises the following steps: (1) in the presence of a first alkaline substance, carrying out a first hydrolysis reaction on dimethyl terephthalate to obtain monomethyl terephthalate; (2) subjecting the monomethyl terephthalate to a contact reaction with a chlorination reagent and ammonia water in sequence so as to obtain methyl 4-carbamoylbenzoate; and (3) carrying out a dehydration reaction on the methyl 4-carbamoylbenzoate to obtain the methyl 4-cyanobenzoate. According to the method for preparing the methyl 4-cyanobenzoate and the method for preparing the 4-cyanobenzoic acid, reaction raw materials are cheap and easy to obtain, and the target compounds can be efficiently prepared in an environment-friendly mode through the processes of hydrolysis, ammoniation, dehydration, optional selection and further hydrolysis.
Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
Bera, Jitendra K.,Pandey, Pragati
supporting information, p. 9204 - 9207 (2021/09/20)
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
Unlocking Amides through Selective C–N Bond Cleavage: Allyl Bromide-Mediated Divergent Synthesis of Nitrogen-Containing Functional Groups
Govindan, Karthick,Chen, Nian-Qi,Chuang, Yu-Wei,Lin, Wei-Yu
supporting information, p. 9419 - 9424 (2021/11/30)
We report a new set of reactions based on the unlocking of amides through simple treatment with allyl bromide, creating a common platform for accessing a diverse range of nitrogen-containing functional groups such as primary amides, sulfonamides, primary amines, N-acyl compounds (esters, thioesters, amides), and N-sulfonyl esters. The method has potential industrial applicability, as demonstrated through gram-scale syntheses in batch and in a continuous flow system.
Ring Opening/Site Selective Cleavage in N-Acyl Glutarimide to Synthesize Primary Amides
Govindan, Karthick,Lin, Wei-Yu
supporting information, p. 1600 - 1605 (2021/03/03)
A LiOH-promoted hydrolysis selective C-N cleavage of twisted N-acyl glutarimide for the synthesis of primary amides under mild conditions has been developed. The reaction is triggered by a ring opening of glutarimide followed by C-N cleavage to afford primary amides using 2 equiv of LiOH as the base at room temperature. The efficacy of the reactions was considered and administrated for various aryl and alkyl substituents in good yield with high selectivity. Moreover, gram-scale synthesis of primary amides using a continuous flow method was achieved. It is noted that our new methodology can apply under both batch and flow conditions for synthetic and industrial applications.
Continuous-Flow Pd-Catalyzed Carbonylation of Aryl Chlorides with Carbon Monoxide at Elevated Temperature and Pressure
Mata, Alejandro,Hone, Christopher A.,Gutmann, Bernhard,Moens, Luc,Kappe, C. Oliver
, p. 997 - 1001 (2019/01/24)
The development of a continuous-flow protocol for a palladium-catalyzed methoxycarbonylation of (hetero)aryl chlorides using carbon monoxide gas and methanol is described. (Hetero)aryl chlorides are the least expensive of the aryl halides, but are underutilized in carbonylation reactions due to their very poor reactivity. The described protocol exploits intensified conditions at elevated temperature and pressure, which are readily accessed within a continuous-flow environment, to provide moderate to excellent product yields (11 examples) in a short 16 min residence time. The continuous-flow protocol enables the safe and potentially scalable carbonylation of aryl chlorides using CO gas.
Nitrile Hydration Reaction Using Copper Iodide/Cesium Carbonate/DBU in Nitromethane-Water
Kuwabara, Jun,Sawada, Yoshiharu,Yoshimatsu, Mitsuhiro
supporting information, p. 2061 - 2065 (2018/09/14)
The catalytic nitrile hydration (amide formation) in a copper iodide/cesium carbonate/1,8-diazabicyclo[5.4.0]undec-7-ene/nitromethane-water system is described. The protocol is robust and reliable; it can be applied to a broad range of substrates with high chemoselectivity.
Copper-Mediated Reactions of Nitriles with Nitromethanes: Aza-Henry Reactions and Nitrile Hydrations
Kuwabara, Jun,Sawada, Yoshiharu,Yoshimatsu, Mitsuhiro
supporting information, p. 1130 - 1133 (2018/02/22)
In this study, the first aza-Henry reaction of nitriles with nitromethane in a CuI/Cs2CO3/DBU system is described. The process was conveniently and directly used for the synthesis of β-aminonitroalkenes 2a-x and tolerated aryl-, alkyl-, hetaryl-, alkenyl-, and alkynylnitriles. The resulting aminonitroalkenes 2 could be successfully transformed to the corresponding 2-nitroacetophenones, 2-amino-1-halonitroalkenes, 2-alkylaminonitroalkenes, or 3-nitropyridines. In the presence of H2O, the aza-Henry reaction turned the reaction path to the nitrile hydration to exclusively yield the amides 3a-s.
A selective hydration of nitriles catalysed by a Pd(OAc)2-based system in water
Sanz Sharley, Daniel D.,Williams, Jonathan M.J.
supporting information, p. 4090 - 4093 (2017/09/27)
In situ formation of a [Pd(OAc)2bipy] (bipy = 2,2′-bipyridyl) complex in water selectively catalyses the hydration of a wide range of organonitriles at 70 °C. Catalyst loadings of 5 mol% afford primary amide products in excellent yields in the absence of hydration-promoting additives such as oximes and hydroxylamines.
Aminocarbonylation of Aryl Halides to Produce Primary Amides by Using NH4HCO3 Dually as Ammonia Surrogate and Base
Wang, Dong-Liang,Liu, Huan,Yang, Da,Wang, Peng,Lu, Yong,Liu, Ye
, p. 4206 - 4211 (2017/12/02)
An efficient and clean protocol was developed for rapid production of primary aromatic amides by aminocarbonylation with NH4HCO3. Without addition of auxiliary base, the use of solid and cheap NH4HCO3 dually as ammonia surrogate and base not only promoted aminocarbonylation over subsequent dehydration and hydrolysis of amides owing to its weak basicity, and it also made the reaction manipulation clean and simplified without the presence of stinky NH3 or organic amines. The Xantphos ligand with relatively intensive π-acceptor character (1J31P–77Se=758 Hz) and wide natural bite angle (βn=111°) was found to be indispensable for the high efficiency of this reaction.
