55390-61-9Relevant articles and documents
Cooperative Catalysis of Ru(III)-Porphyrin in CO2-Involved Synthesis of Oxazolidinones
Chen, Xiao-Chao,Yao, Yin-Qing,Zhao, Kai-Chun,Liu, Lei,Lu, Yong,Liu, Ye
, p. 2504 - 2510 (2021/07/28)
CO2-transformations into high value-added products have become a fascinating area in green chemistry. Herein, a Ru(III)-porphyrin catalyst (RuCl3 ? 3H2O?H2TPP) was found highly efficient in the three-component reaction of CO2, aliphatic amines and dichloroethane (or its derivative) for synthesis of oxazolidinones in the yields of 71～91%. It was indicated by means of the control experiments and UV-vis spectra that CO2 was stoichiometrically activated by the involved aliphatic amine substrates to form a stable carbamate salt while 1,2-dichloroethane (or its derivative) was independently activated by the involved Ru(III)-porphyrin catalyst. The combination of CO2-activation by aliphatic amines with 1,2-dichloroethane activation by Ru(III)-porphyrin catalyst cooperatively contributed to this successful transformation.
Synergetic activation of CO2by the DBU-organocatalyst and amine substrates towards stable carbamate salts for synthesis of oxazolidinones
Chen, Xiao-Chao,Liu, Ye,Lu, Yong,Yao, Yin-Qing,Zhao, Kai-Chun
, p. 7072 - 7082 (2021/11/17)
The development of an efficient methodology to transform CO2 into valuable chemicals has attracted increasing attention concerning the challenging issues of CO2-utilization. Herein, an efficient approach for the preparation of oxazolidinones from CO2, primary (aliphatic/aromatic) amines and 1,2-dichloroethane (or its derivatives) catalyzed by DBU organo-superbase was achieved with yields of 47-97% under mild conditions (80-100 °C, 12 h, 1.0 MPa CO2). Control experiments demonstrated that the formation of an ion-pair carbamate salt intermediate IS-B derived from the reaction of CO2, DBU (catalyst) and an amine (substrate) was the key step for this three-component reaction. The available DBU-amine-CO2 adduct intermediate (like IS-B-2) with fair stability will evolve into the thermodynamically stable product oxazolidinones upon attack of 1,2-dichloroethane (or its derivatives), along with the regeneration of the DBU catalyst. Alternatively, the decomposition of the DBU-aryl amine-CO2 adduct (like IS-B-1) with relatively poor stability also could result in the competitive substitution reaction of 1,2-dichloroethane (or its derivatives) with the aryl amine. This work provides insights into synergetic CO2-activation by the DBU-catalyst and a nucleophilic amine-substrate via the formation of robust carbamate salt intermediates responsible for the final production of oxazolidinones. This journal is
Decarboxylative sp 3 C-N coupling via dual copper and photoredox catalysis
Liang, Yufan,Zhang, Xiaheng,MacMillan, David W. C.
, p. 83 - 88 (2018/07/24)
Over the past three decades, considerable progress has been made in the development of methods to construct sp 2 carbon-nitrogen (C-N) bonds using palladium, copper or nickel catalysis 1,2 . However, the incorporation of alkyl substrates to form sp 3 C-N bonds remains one of the major challenges in the field of cross-coupling chemistry. Here we demonstrate that the synergistic combination of copper catalysis and photoredox catalysis can provide a general platform from which to address this challenge. This cross-coupling system uses naturally abundant alkyl carboxylic acids and commercially available nitrogen nucleophiles as coupling partners. It is applicable to a wide variety of primary, secondary and tertiary alkyl carboxylic acids (through iodonium activation), as well as a vast array of nitrogen nucleophiles: nitrogen heterocycles, amides, sulfonamides and anilines can undergo C-N coupling to provide N-alkyl products in good to excellent efficiency, at room temperature and on short timescales (five minutes to one hour). We demonstrate that this C-N coupling protocol proceeds with high regioselectivity using substrates that contain several amine groups, and can also be applied to complex drug molecules, enabling the rapid construction of molecular complexity and the late-stage functionalization of bioactive pharmaceuticals.
DBU and DBU-Derived Ionic Liquid Synergistic Catalysts for the Conversion of Carbon Dioxide/Carbon Disulfide to 3-Aryl-2-oxazolidinones/[1,3]Dithiolan-2-ylidenephenyl- Amine
Wang, Binshen,Luo, Zhoujie,Elageed, Elnazeer H. M.,Wu, Shi,Zhang, Yongya,Wu, Xiaopei,Xia, Fei,Zhang, Guirong,Gao, Guohua
, p. 830 - 838 (2016/03/05)
An intermolecular synergistic catalytic combination of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and a DBU-derived bromide ionic liquid has been developed for the conversion of CO2, epoxides, and amines under metal- And solvent-free conditions. Various 3-aryl-2-oxazolidinones are produced in moderate to excellent yields within a short reaction time. NMR spectroscopy and DFT calculations demonstrate that DBU as a hydrogen bond acceptor and the ionic liquid as a hydrogen bond donor activate the substrates cooperatively by inducing hydrogen bonds to promote the reaction effectively. Based on these results, a possible reaction mechanism on the synergistic catalysis of DBU and the ionic liquid is proposed. In addition, the reaction of CS2, ethylene oxide, and aniline catalyzed by the combination of DBU and the DBU-derived ionic liquid also proceeds smoothly, which opens a hitherto unreported route to [1,3]dithiolan-2-ylidenephenylamine in a straightforward way.
Photoinduced, copper-catalyzed alkylation of amides with unactivated secondary alkyl halides at room temperature
Do, Hien-Quang,Bachman, Shoshana,Bissember, Alex C.,Peters, Jonas C.,Fu, Gregory C.
supporting information, p. 2162 - 2167 (2014/03/21)
The development of a mild and general method for the alkylation of amides with relatively unreactive alkyl halides (i.e., poor substrates for S N2 reactions) is an ongoing challenge in organic synthesis. We describe herein a versatile transition-metal-catalyzed approach: in particular, a photoinduced, copper-catalyzed monoalkylation of primary amides. A broad array of alkyl and aryl amides (as well as a lactam and a 2-oxazolidinone) couple with unactivated secondary (and hindered primary) alkyl bromides and iodides using a single set of comparatively simple and mild conditions: inexpensive CuI as the catalyst, no separate added ligand, and C-N bond formation at room temperature. The method is compatible with a variety of functional groups, such as an olefin, a carbamate, a thiophene, and a pyridine, and it has been applied to the synthesis of an opioid receptor antagonist. A range of mechanistic observations, including reactivity and stereochemical studies, are consistent with a coupling pathway that includes photoexcitation of a copper-amidate complex, followed by electron transfer to form an alkyl radical.
One-pot conversion of carbon dioxide, ethylene oxide, and amines to 3-aryl-2-oxazolidinones catalyzed with binary ionic liquids
Wang, Binshen,Elageed, Elnazeer H.M.,Zhang, Dawei,Yang, Sijuan,Wu, Shi,Zhang, Guirong,Gao, Guohua
, p. 278 - 283 (2014/01/23)
An effective one-pot method for the conversion of carbon dioxide, ethylene oxide, and amines to 3-aryl-2-oxazolidinones has been developed. This one-pot method consists of two parallel reactions and a subsequent cascade reaction between the two products of the corresponding parallel reactions. Notably, the binary ionic liquids of 1-butyl-3-methyl-imidazolium bromide and 1-butyl-3-methyl-imidazolium acetate demonstrate a synergistic catalytic effect on this new strategy. 1-Butyl-3-methyl-imidazolium bromide is essential in two parallel reactions owing to the good nucleophilicity and leaving ability of bromide, and 1-butyl-3-methyl-imidazolium acetate plays a dominant role in the subsequent cascade reaction owing to the strong basicity of acetate. In addition, the binary ionic liquids can be used thrice without significant loss of catalytic activity. Copyright
Copper-catalyzed intermolecular amidation and imidation of unactivated alkanes
Tran, Ba L.,Li, Bijie,Driess, Matthias,Hartwig, John F.
supporting information, p. 2555 - 2563 (2014/03/21)
We report a set of rare copper-catalyzed reactions of alkanes with simple amides, sulfonamides, and imides (i.e., benzamides, tosylamides, carbamates, and phthalimide) to form the corresponding N-alkyl products. The reactions lead to functionalization at secondary C-H bonds over tertiary C-H bonds and even occur at primary C-H bonds. [(phen)Cu(phth)] (1-phth) and [(phen)Cu(phth)2] (1-phth2), which are potential intermediates in the reaction, have been isolated and fully characterized. The stoichiometric reactions of 1-phth and 1-phth2 with alkanes, alkyl radicals, and radical probes were investigated to elucidate the mechanism of the amidation. The catalytic and stoichiometric reactions require both copper and tBuOOtBu for the generation of N-alkyl product. Neither 1-phth nor 1-phth2 reacted with excess cyclohexane at 100 C without tBuOOtBu. However, the reactions of 1-phth and 1-phth2 with tBuOOtBu afforded N-cyclohexylphthalimide (Cy-phth), N-methylphthalimide, and tert-butoxycyclohexane (Cy-OtBu) in approximate ratios of 70:20:30, respectively. Reactions with radical traps support the intermediacy of a tert-butoxy radical, which forms an alkyl radical intermediate. The intermediacy of an alkyl radical was evidenced by the catalytic reaction of cyclohexane with benzamide in the presence of CBr4, which formed exclusively bromocyclohexane. Furthermore, stoichiometric reactions of [(phen)Cu(phth)2] with tBuOOtBu and (Ph(Me)2CO) 2 at 100 C without cyclohexane afforded N-methylphthalimide (Me-phth) from β-Me scission of the alkoxy radicals to form a methyl radical. Separate reactions of cyclohexane and d12-cyclohexane with benzamide showed that the turnover-limiting step in the catalytic reaction is the C-H cleavage of cyclohexane by a tert-butoxy radical. These mechanistic data imply that the tert-butoxy radical reacts with the C-H bonds of alkanes, and the subsequent alkyl radical combines with 1-phth2 to form the corresponding N-alkyl imide product.
Stereoselective direct reductive amination of ketones with electron-deficient amines using Re2O7/NaPF6 catalyst
Das, Braja Gopal,Ghorai, Prasanta
supporting information, p. 4379 - 4382 (2013/08/23)
The first example of direct reductive amination (DRA) of ketones with electron-deficient amines (EDA) such as Cbz-, Boc-, EtOCO-, Fmoc-, Bz-, ArSO2-, etc. protected amines have been achieved using catalytic Re2O7/NaPF6. Excellent chemoselectivities as well as diastereoselectivity (for 2-alkyl cyclohexanones) were obtained. The Royal Society of Chemistry 2013.
