55390-61-9Relevant articles and documents
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.
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.
