20383-28-2Relevant academic research and scientific papers
Conformational Equilibria and Torsional Barriers of the Isopropyl Groups in N,N-Diisopropylbenzamide and its Thio and Seleno Analogues
Berg, Ulf,Pettersson, Ingrid
, p. 536 - 539 (1985)
The conformations of the isopropyl groups and the barriers to conformational interconversion in N,N-diisopropylbenzamide (1), and its thio (2) and seleno (3) analogues have been studied by dynamic 1H NMR spectroscopy.In 1 only one conformation is observed
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.
, p. 4490 - 4493 (2021)
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.
Gram-Scale Preparation of Acyl Fluorides and Their Reactions with Hindered Nucleophiles
Tryniszewski, Micha?,Barbasiewicz, Micha?
, p. 1446 - 1460 (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.
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.
A Fast and General Route to Ketones from Amides and Organolithium Compounds under Aerobic Conditions: Synthetic and Mechanistic Aspects
Ghinato, Simone,Territo, Davide,Maranzana, Andrea,Capriati, Vito,Blangetti, Marco,Prandi, Cristina
supporting information, p. 2868 - 2874 (2021/01/21)
We report that the nucleophilic acyl substitution reaction of aliphatic and (hetero)aromatic amides by organolithium reagents proceeds quickly (20 s reaction time), efficiently, and chemoselectively with a broad substrate scope in the environmentally responsible cyclopentyl methyl ether, at ambient temperature and under air, to provide ketones in up to 93 % yield with an effective suppression of the notorious over-addition reaction. Detailed DFT calculations and NMR investigations support the experimental results. The described methodology was proven to be amenable to scale-up and recyclability protocols. Contrasting classical procedures carried out under inert atmospheres, this work lays the foundation for a profound paradigm shift of the reactivity of carboxylic acid amides with organolithiums, with ketones being straightforwardly obtained by simply combining the reagents under aerobic conditions and with no need of using previously modified or pre-activated amides, as recommended.
Rhoda-Electrocatalyzed Bimetallic C?H Oxygenation by Weak O-Coordination
Tan, Xuefeng,Massignan, Leonardo,Hou, Xiaoyan,Frey, Johanna,Oliveira, Jo?o C. A.,Hussain, Masoom Nasiha,Ackermann, Lutz
supporting information, p. 13264 - 13270 (2021/05/06)
Rhodium-electrocatalyzed arene C?H oxygenation by weakly O-coordinating amides and ketones have been established by bimetallic electrocatalysis. Likewise, diverse dihydrooxazinones were selectively accessed by the judicious choice of current, enabling twofold C?H functionalization. Detailed mechanistic studies by experiment, mass spectroscopy and cyclovoltammetric analysis provided support for an unprecedented electrooxidation-induced C?H activation by a bimetallic rhodium catalysis manifold.
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.
Thioxanthone synthesis from benzoic acid esters through directed ortho-lithiation
Hosoya, Takamitsu,Kobayashi, Akihiro,Matsuzawa, Tsubasa,Yoshida, Suguru
supporting information, p. 1624 - 1627 (2021/08/30)
An efficient synthetic method for thioxanthones from 3-halobenzoic acid esters is disclosed. Directed ortho-lithiation of 3-halobenzoic acid esters and following arylthiolation realized the synthesis of sterically congested 2-(arylthio)-3-halobenzoic acid
Asymmetric Transfer Hydrogenation of o-Hydroxyphenyl Ketones: Utilizing Directing Effects That Optimize the Asymmetric Synthesis of Challenging Alcohols
Clarkson, Guy J.,Wills, Martin,Zheng, Ye
supporting information, (2020/05/05)
A systematic range of o-hydroxyphenyl ketones were reduced under asymmetric transfer hydrogenation conditions using the C3-tethered catalyst 2. Two directing effects, i.e., an o-hydroxyphenyl coupled to a bulky aromatic on the opposite side of the ketone substrate, combine in a matched manner to deliver reduction products with very high enantiomeric excess.
Ruthenium(II)-catalyzed C-H arylation of N,N-dialkyl thiobenzamides with boronic acids by sulfur coordination in 2-MeTHF
Zhang, Jin,Liu, Ying,Jia, Qiangqiang,Wang, Yue,Ma, Yangmin,Szostak, Michal
supporting information, p. 6884 - 6890 (2020/09/15)
We report ruthenium(II)-catalyzed ortho-C-H arylation of N,N-dialkylthiobenzamides with boronic acids. The method employs [RuCl2(p-cym)]2 in the presence of Cu(OTf)2 and Ag2O oxidant. The reaction represents the first example of Ru-catalyzed C-H arylation directed by sulfur-containing groups and a rare example of C-H arylation directed by the versatile thiobenzamide moiety. As a further advantage, the method is performed in sustainable and eco-friendly 2-MeTHF as a solvent.
