122334-37-6Relevant academic research and scientific papers
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.
A CO2-Catalyzed Transamidation Reaction
Yang, Yang,Liu, Jian,Kamounah, Fadhil S.,Ciancaleoni, Gianluca,Lee, Ji-Woong
, p. 16867 - 16881 (2021/11/18)
Transamidation reactions are often mediated by reactive substrates in the presence of overstoichiometric activating reagents and/or transition metal catalysts. Here we report the use of CO2as a traceless catalyst: in the presence of catalytic amounts of CO2, transamidation reactions were accelerated with primary, secondary, and tertiary amide donors. Various amine nucleophiles including amino acid derivatives were tolerated, showcasing the utility of transamidation in peptide modification and polymer degradation (e.g., Nylon-6,6). In particular,N,O-dimethylhydroxyl amides (Weinreb amides) displayed a distinct reactivity in the CO2-catalyzed transamidation versus a N2atmosphere. Comparative Hammett studies and kinetic analysis were conducted to elucidate the catalytic activation mechanism of molecular CO2, which was supported by DFT calculations. We attributed the positive effect of CO2in the transamidation reaction to the stabilization of tetrahedral intermediates by covalent binding to the electrophilic CO2
Phase-Transfer Catalyzed Asymmetric [4 + 1] Annulations for the Synthesis of Chiral 2,2-Disubstituted Tetrahydrothiophenes
Yin, Qi,Wen, Xiaolu,Chen, Yiwei,Gong, Xiangnan,Hu, Lin
supporting information, p. 7529 - 7534 (2021/10/02)
An efficient catalytic asymmetric [4 + 1] reaction, which features the use of simple β-keto esters as one-carbon nucleophiles and 5-succinimidothio-pent-2-enoates as four-atom bielectrophiles, has been developed in the presence of a bifunctional chiral ph
Synthesis of various acylating agents directly from carboxylic acids
Pilathottathil, Fathima,Vineet Kumar, Doppalapudi,Kaliyamoorthy, Alagiri
supporting information, p. 1622 - 1632 (2020/04/27)
A straightforward synthesis of acylating reagents such as Weinreb and MAP amides from aromatic, aliphatic carboxylic acids, and amino acids using PPh3/NBS combination is described. A chemo-selective modification of the carboxylic acid group into Weinreb amide in the presence of more reactive aldehydes and ketones is presented. All reactions were performed at ambient temperature under air using undried commercial grade solvent. Furthermore, the present methodology could be performed at a gram scale under inert-free reaction conditions. In addition, 7-azaindoline amide auxiliary (used for catalytic asymmetric aldol- and Mannich-type reactions), which behaves like Weinreb amide is also synthesized under similar reaction conditions.
Iron-Catalyzed, Iminyl Radical-Triggered Cascade 1,5-Hydrogen Atom Transfer/(5+2) or (5+1) Annulation: Oxime as a Five-Atom Assembling Unit
Chen, Ying-Chun,Du, Fei,Jiang, Kun,Liang, Wu,Ouyang, Qin,Shuai, Li,Wei, Ye,Yang, Jie
supporting information, p. 19222 - 19228 (2020/08/25)
By integration of iminyl radical-triggered 1,5-hydrogen atom transfer and (5+2) or (5+1) annulation processes, a series of structurally novel and interesting azepine and spiro-tetrahydropyridine derivatives have been successfully prepared in moderate to good yields. This method utilizes FeCl2 as the catalyst and readily available oximes as five-atom units, while showcasing broad substrate scope and good functional group compatibility. The annulation products can be easily converted into many valuable compounds. Moreover, DFT calculation studies are performed to provide some insights into the possible reaction mechanisms for the (5+2) and (5+1) annulations.
Saturated Bioisosteres of ortho-Substituted Benzenes
Denisenko, Aleksandr,Garbuz, Pavel,Mykhailiuk, Pavel K.,Shishkina, Svetlana V.,Voloshchuk, Nataliya M.
supporting information, p. 20515 - 20521 (2020/08/21)
Saturated bioisosteres of ortho-disubstituted benzenes (bicyclo[2.1.1]hexanes) were synthesized, characterized and validated. These cores were incorporated into the bioactive compounds Valsartan, Boskalid and Fluxapyroxad instead of the benzene ring. The
Br?nsted Base-Catalyzed Transformation of α,β-Epoxyketones Utilizing [1,2]-Phospha-Brook Rearrangement for the Synthesis of Allylic Alcohols Having a Tetrasubstituted Alkene Moiety
Kondoh, Azusa,Tasato, Naoko,Aoki, Takuma,Terada, Masahiro
supporting information, p. 5170 - 5175 (2020/07/04)
A stereoselective transformation of α,β-epoxyketones into alkenylphosphates having a hydroxymethyl group on the β-carbon was established by utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis. The reaction involves the catalytic generation of an α-oxygenated carbanion located at the α-position of an epoxide moiety through the [1,2]-phospha-Brook rearrangement and the following epoxide opening. Further transformation of the alkenylphosphates by the palladium-catalyzed cross-coupling reaction with Grignard reagents provided allylic alcohols having a stereodefined all-carbon tetrasubstituted alkene moiety.
Formation of Aryl [1-Cyano-4-(dialkylamino)butadienyl] Ketones from Pyridines
Gim, Hyo Jin,Jung, Michael E.
supporting information, p. 2548 - 2552 (2019/06/08)
Treatment of 2-chloropyridine with LDA and the Weinreb amide of benzoic acid afforded three unusual products, namely N -methylbenzamide, 2-chloropyridine-3-methanol, and the ring-opened addition product. This same final product could also be obtained from 2-chloro-3-benzoylpyridine on treatment with LDA. Mechanistic insight for the formation of these products is provided.
Iminyl Radicals by Reductive Cleavage of N-O Bond in Oxime Ether Promoted by SmI2: A Straightforward Synthesis of Five-Membered Cyclic Imines
Huang, Fei,Zhang, Songlin
supporting information, p. 7430 - 7434 (2019/10/11)
A new generation method of N-centered radicals from the reductive cleavage of the N-O bond in oxime ether promoted by SmI2 is reported for the first time. The in-situ-generated N-centered radicals underwent intramolecular cyclization to afford five-membered cyclic imines in two manners: N-centered radical addition and N-centered anion nucleophilic substitution. From a synthetic point of view, an efficient synthetic method of five-membered cyclic imines was developed. A mechanism of the transformation was proposed.
Mo(CO)6 as a Solid CO Source in the Synthesis of Aryl/Heteroaryl Weinreb Amides under Microwave-Enhanced Condition
Ningegowda, Raghu,Bhaskaran, Savitha,Sajith, Ayyiliath M.,Aswathanarayanappa, Chandrashekar,Padusha, M. Syed Ali,Priya, Babu Shubha
, p. 44 - 51 (2017/01/21)
The facile transformation of aryl/heteroaryl nonaflates into corresponding amides via Pd-catalyzed aminocarbonylation using Mo(CO)6 as a solid CO source under microwave-enhanced condition is reported. The method was found to be tolerant with respect to a
