52807-29-1Relevant academic research and scientific papers
Chiroptical molecular propellers based on hexakis(phenylethynyl)benzene through the complexation-induced intramolecular transmission of local point chirality
Katoono, Ryo,Kusaka, Keiichi,Kawai, Shunsuke,Tanaka, Yuki,Hanada, Keisuke,Nehira, Tatsuo,Fujiwara, Kenshu,Suzuki, Takanori
, p. 9532 - 9538 (2014)
We designed hexakis(phenylethynyl)benzene derivatives with a tertiary amide group on each blade to achieve a helically biased propeller arrangement through the complexation-induced intramolecular transmission of point chirality. A hydrogen-bonding ditopic
Metal-free transamidation of benzoylpyrrolidin-2-one and amines under aqueous conditions
Joseph, Devaneyan,Lee, Sunwoo,Park, Myeong Seong
supporting information, p. 6227 - 6232 (2021/07/28)
N-Acyl lactam amides, such as benzoylpyrrolidin-2-one, benzoylpiperidin-2-one, and benzoylazepan-2-one reacted with amines in the presence of DTBP and TBAI to afford the transamidated products in good yields. The reactions were conducted under aqueous conditions and good functional group tolerance was achieved. Both aliphatic and aromatic primary amines displayed good activity under metal-free conditions. A radical reaction pathway is proposed.
Manganese Catalyzed Direct Amidation of Esters with Amines
Fu, Zhengqiang,Wang, Xinghua,Tao, Sheng,Bu, Qingqing,Wei, Donghui,Liu, Ning
, p. 2339 - 2358 (2021/02/03)
The transition metal catalyzed amide bond forming reaction of esters with amines has been developed as an advanced approach for overcoming the shortcomings of traditional methods. The broad scope of substrates in transition metal catalyzed amidations remains a challenge. Here, a manganese(I)-catalyzed method for the direct synthesis of amides from a various number of esters and amines is reported with unprecedented substrate scope using a low catalyst loading. A wide range of aromatic, aliphatic, and heterocyclic esters, even in fatty acid esters, reacted with a diverse range of primary aryl amines, primary alkyl amines, and secondary alkyl amines to form amides. It is noteworthy that this approach provides the first example of the transition metal catalyzed amide bond forming reaction from fatty acid esters and amines. The acid-base mechanism for the manganese(I)-catalyzed direct amidation of esters with amines was elucidated by DFT calculations.
Synthesis of 2-Amino-1,3-dienes from Propargyl Carbonates via Palladium-Catalyzed Carbon-Nitrogen Bond Formation
O'Broin, Calvin Q.,Guiry, Patrick J.
supporting information, p. 879 - 883 (2020/02/04)
A catalytic method to synthesize 1,3,-dienes from propargylic precursors is reported. This palladium-catalyzed carbon-nitrogen bond-forming reaction furnishes 2-amino-1,3-dienes in excellent yields (up to 98%) and shows a broad tolerance to functional group diversity. The reaction has been demonstrated for over 30 amine substrates, including anilines and indoles, and proceeds under mild neutral conditions. The resulting 1,3-dienes are of great synthetic interest because of their further reaction potential.
Mechanochemical Synthesis of N-Aryl Amides from O-Protected Hydroxamic Acids
Broumidis, Emmanouil,Jones, Mary C.,Lloyd, Gareth O.,Vilela, Filipe
, p. 1754 - 1761 (2020/09/02)
Two robust and efficient mechanochemical protocols for the synthesis of an array of N-arylamides have been developed. This was achieved by a C?N cross-coupling between O-pivaloyl hydroxamic acids and aryl iodides or aryl boronic acids, in the presence of a stoichiometric amount of a copper mediator. The effectiveness of this method is highlighted by the high-yielding (up to 94 %), scalable (up to 8 mmol), and rapid (20 minutes) synthesis of N-aryl amides (15 examples), using a variety of deactivated and sterically encumbered substrates, whilst employing mild conditions and in the absence of solvents. In addition, it was determined that whilst the O-pivaloyl hydroxamic acid precursors can be synthesised mechanochemically, iron contamination originating from the steel jars was found to occur which can hinder the efficacy of this process. Furthermore, 3D printing was used to produce custom milling jars that could successfully accommodate a scaled-up version of the two protocols.
Electrochemical Radical Borylation of Aryl Iodides
Hong, Junting,Liu, Qianyi,Li, Feng,Bai, Guangcan,Liu, Guoquan,Li, Man,Nayal, Onkar S.,Fu, Xuefeng,Mo, Fanyang
supporting information, p. 347 - 351 (2019/03/07)
Herein, we report the first electrochemical strategy for the borylation of aryl iodides via a radical pathway using current as a driving force. A mild reaction condition allows an assorted range of readily available aryl iodides to be proficiently converted into synthetically valuable arylboronic esters under transition metal catalyst-free conditions. Moreover, this method also shows good functional group tolerance. Initial control mechanistic experiments reveal the formation of aryl radical as a key intermediate and the current plays an important role in the generation of radical intermediate.
Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C-H Thiolation via Reverse Hydrogen Atom Transfer
Xu, Ze-Ming,Li, Hong-Xi,Young, David James,Zhu, Da-Liang,Li, Hai-Yan,Lang, Jian-Ping
supporting information, p. 237 - 241 (2019/01/10)
Visible-light-driven, intramolecular C(sp2)-H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.
Synthesis of Arylamides via Ritter-Type Cleavage of Solid-Supported Aryltriazenes
Wippert, Nicolai A.,Jung, Nicole,Br?se, Stefan
supporting information, p. 568 - 572 (2019/09/03)
A novel route for the synthesis of N-arylamides via the cleavage of aryltriazenes with alkyl or aryl nitriles is presented. We developed a variation of the Ritter reaction that allows the use of acetonitrile as solvent and reagent in reactions with solid-supported precursors. The reaction was optimized for the generation of N-aryl acetamides using a diverse range of immobilized building blocks including o-, m-, and p-substituted aryltriazenes. The cleavage via the Ritter-type conversion was combined with an on-bead cross-coupling reaction of halogen-substituted aryltriazenes with pyrazoles. Additionally, the synthesis of on-bead generated arylboronic ester-substituted triazenes was shown. The developed procedure was further expanded to use other commercially available nitriles, such as acrylonitrile, benzonitrile, and chlorinated alkyl nitriles as suitable reagents for a Ritter-type cleavage of the prepared triazene linkers.
Amide Synthesis from Thiocarboxylic Acids and Amines by Spontaneous Reaction and Electrosynthesis
Tang, Li,Matuska, Jack H.,Huang, Yu-Han,He, Yan-Hong,Guan, Zhi
, p. 2570 - 2575 (2019/06/13)
Amide bond formation is one of the most important basic reactions in chemistry. A catalyst-free approach for constructing amide bonds from thiocarboxylic acids and amines was developed. The mechanistic studies showed that the disulfide was the key intermediate for this amide synthesis. Thiobenzoic acids could be automatically oxidized to disulfides in air, thioaliphatic acids could be electro-oxidized to disulfides, and the resulting disulfides reacted with amines to give the corresponding amides. By this method, various amides could be easily synthesized in excellent yields without using any catalyst or activator. The successful synthesis of bioactive compounds also highlights the synthetic utility of this strategy in medicinal chemistry.
Catalyst-Free, Metal-Free, and Chemoselective Transamidation of Activated Secondary Amides
Ramkumar, Rajagopal,Chandrasekaran, Srinivasan
, p. 921 - 932 (2019/02/10)
A simple protocol, which is catalyst-free, metal-free, and chemoselective, for transamidation of activated secondary amides in ethanol as solvent under mild conditions is reported. A wide range of amines, amino acids, amino alcohols, and the substituents, which are problematic in catalyzed transamidation, are tolerated in this methodology. The transamidation reaction was successfully extended to water as the medium as well. The present methodology appears to be better than the other catalyzed transamidations reported recently.
