6971-74-0Relevant academic research and scientific papers
Chemoselective Cleavage of Acylsulfonamides and Sulfonamides by Aluminum Halides
Sang, Dayong,Dong, Bingqian,Liu, Yunfeng,Tian, Juan
, p. 3586 - 3595 (2022/02/25)
The chemoselective cleavage of C-N bonds of amides, sulfonamides, and acylsulfonamides by aluminum halides is described. AlCl3and AlI3display complementary reactivities toward N-alkyl and N-acyl moieties. N-Alkylacylsulfonamides, sec
N-Aroylsulfonamide-Photofragmentation (ASAP)-A Versatile Route to Biaryls
Wessig, Pablo,Krebs, Saskia
supporting information, p. 6367 - 6374 (2021/09/29)
The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The ASAP mechanism was elucidated by interaction of photophysical and quantum chemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.
Controlled Relay Process to Access N-Centered Radicals for Catalyst-free Amidation of Aldehydes under Visible Light
Chang, Sukbok,Jeon, Hyun Ji,Jung, Hoimin,Kim, Dongwook,Lee, Wongyu,Seo, Sangwon
supporting information, p. 495 - 508 (2021/01/28)
Nitrogen-centered radicals have attracted increasing attention as a versatile reactive intermediate for diverse C–N bond constructions. Despite the significant advances achieved in this realm, the controllable formation of such species under catalyst-free conditions remains highly challenging. Here, we report a new relay process involving the slow in situ generation of a photoactive N-chloro species via C–N bond formation, which subsequently enables mild and selective access to N-centered radicals under visible light conditions. The utility of this approach is demonstrated by the conversion of aldehydes to amides, employing N-chloro-N-sodio carbamates as a practical amidating source. This synthetic operation obviates the need for catalysts, external oxidants, and coupling reagents that are typically required in related processes, consequently allowing high functional group tolerance and excellent applicability for late-stage functionalization. Amides are an important class of structural motifs prevalently found in bioactive compounds and synthetic materials of great significance. Amidation of aldehydes has been established as an atom-efficient strategy for amide synthesis; however, current methods lack in applicability mainly due to the requirement of troublesome reagents. In this article, we describe an unconventional relay process to convert aldehydes to amides under catalyst-, oxidant-, and coupling-reagent-free conditions, which is enabled by the development of a new mechanistic platform that gives efficient and controllable access to N-centered radicals under visible light. A wide range of (hetero)aromatic and aliphatic aldehydes can be employed, including those derived from biologically relevant complex molecules. We anticipate that the accomplished methodological advances, combined with the unique mechanistic features, will lead to the widespread application of the present strategy in broad research fields. A catalyst-free approach for controlled access to N-centered radicals is described, which enables the conversion of aldehydes to amides via an unconventional relay process harnessing visible light. The key tactic relies on the use of photostable N-chloro-N-sodio-carbamate amidating reagent that leads to slow incorporations of a photoactive radical source via C–N formation and other involved intermediates thereafter. This methodology displays excellent applicability and sustainable chemistry credentials and, thus, holds a promise for finding broad applications.
NOVEL AMIDATION METHOD
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Paragraph 0104-0110; 0121, (2021/09/21)
The present invention relates to a novel amidation process. To the present invention, an active N -center radical activated by light irradiation can be utilized to provide a selective amidation method. In addition, the present invention can provide an amide compound derived from an aldehyde having a functional group of various aspects, and is expected to be applicable to various technical fields.
Ru(ii)-catalyzed allenylation and sequential annulation of: N -tosylbenzamides with propargyl alcohols
Kumar, Shreemoyee,Nair, Akshay M.,Volla, Chandra M. R.
, p. 6280 - 6283 (2021/07/02)
We hereby report Ru(ii)-catalyzed C(sp2)-H allenylation of N-tosylbenzamides to access multi-substituted allenylamides. Furthermore, the allenylamides were converted to the corresponding isoquinolone derivatives via base mediated annulation. The current protocol features low catalyst loading, mild reaction conditions, high functional group compatibility and desired scalability. The unique functionality of the afforded allenes allowed further transformations to expand the practicality of the protocol. This journal is
Synthesis of 2-Imidazolines via Palladium-Catalyzed Cyclization Reaction of 2,3-Allenyl Amines and Aryl Iodides
Fang, Zixuan,Hu, Jinxing,Liang, Xiaoxia,Liu, Yanjun,Liu, Yue,Lu, Rongmei,Wang, Shaoyu,Zeng, Xianzhong,Zhang, Cheng
supporting information, p. 901 - 908 (2020/03/13)
An effective method for the synthesis of polysubstituted 2-imidazoline derivatives via palladium-catalyzed cyclization of 2,3-allenyl amines with aryl iodides is described. This pure domino process allows the formation of new carbon-carbon and carbon-nitrogen bonds in a single synthetic operation.
Vinylogous Elimination/C-H Functionalization/Allylation Cascade Reaction of Allenoate Adducts: Synthesis of Ring-Fused Dihydropyridinones
Sun, Manman,Chen, Weida,Wu, Haijian,Xia, Xiangyu,Yang, Jianguo,Wang, Lei,Shen, Guodong,Wang, Zhiming
supporting information, p. 8313 - 8319 (2020/11/03)
A palladium-catalyzed cascade reaction of β′-allenoate adducts with aryl/heteroaryl carboxamides through a vinylogous elimination/C-H functionalization/intramolecular allylation reaction sequence has been developed with high Z stereoselectivity. Various ring-fused dihydropyridinones bearing an α,β-unsaturated ester substituent are obtained. It is the first example of application of the allenoate adducts to C-H functionalization annulations as practical precursors of hard-to-get functionalized electron-deficient 1,3-butadienes. Using air as the terminal oxidant also shows a great advantage in environmental friendliness.
Stereoselective and Atom-Economic Alkenyl C-H Allylation/Alkenylation in Aqueous Media by Iridium Catalysis
Ding, Liyuan,Huang, Yinhua,Lu, Xiunan,Shen, Wenzhou,Xu, Liangyao,Yu, Feifei,Zhang, Jian,Zhong, Guofu,Zhong, Liangjun
, p. 7225 - 7237 (2020/07/07)
A practical and atom-economic protocol for the stereoselective preparation of various 1,4-and 1,3-diene skeletons through iridium-catalyzed directed olefinic C-H allylation and alkenylation of NH-Ts acrylamides in water was developed. This reaction tolerated a wide scope of substrates under simple reaction conditions and enabled successful gram-scale preparation. Furthermore, an asymmetric variant of this reaction giving enantioenriched 1,4-dienes was achieved employing a chiral diene-iridium complex as the catalyst.
Metal-free C-H Activation over Graphene Oxide toward Direct Syntheses of Structurally Different Amines and Amides in Water
Shukla, Prashant,Asati, Ambika,Bhardiya, Smita R.,Singh, Manorama,Rai, Vijai K.,Rai, Ankita
, p. 15552 - 15561 (2020/12/02)
Unprecedented metal-free synthesis of a variety of amines and amides is reported via amination of C(sp3)-H and C(sp2)-H bonds. The strategy involves graphene-oxide/I2-catalyzed nitrene insertion using PhINTs as a nitrene (NT) source in water at room temperature. A wide range of structurally different substrates, viz., cyclohexane, cyclic ethers, arenes, alkyl aromatic systems, and aldehydes/ketones, having an α-phenyl ring have been employed successfully to afford the corresponding nitrene insertion product in good yield, albeit low in few cases. The envisaged method has superiority over others in terms of its operational simplicity, metal-free catalysis, use of water as a solvent, ambient reaction conditions, and reusability of the catalyst.
Ruthenium-Catalyzed Synthesis of Isoindolinones via Amide-Directed Addition of Aromatic C-H Bonds to Aldimines
Miura, Hiroki,Kimura, Yuriko,Terajima, Sachie,Shishido, Tetsuya
supporting information, p. 2807 - 2811 (2019/02/01)
Ruthenium-catalyzed addition of aromatic C-H bonds to aldimines is described. [RuCl2(p-cymene)]2 functions as an efficient catalyst to promote the coupling of aryl amides with aldimines in the presence of a catalytic amount of base to give the corresponding isoindolinone derivatives. The nature of the substituent at the N-atom of the amides is crucial for the efficient conversion of the substrates, and a p-toluenesulfonyl group is the functionality of choice. A variety of amides and aldimines participated in the present Ru-catalyzed reaction to furnish the corresponding isoindolinones in moderate to high yield.
