20925-24-0Relevant articles and documents
Photocatalytic Water-Splitting Coupled with Alkanol Oxidation for Selective N-alkylation Reactions over Carbon Nitride
Xu, Yangsen,Zhang, Zhaofei,Qiu, Chuntian,Chen, Shaoqin,Ling, Xiang,Su, Chenliang
, p. 582 - 589 (2020/12/09)
Photocatalytic water splitting technology (PWST) enables the direct use of water as appealing “liquid hydrogen source” for transfer hydrogenation reactions. Currently, the development of PWST-based transfer hydrogenations is still in an embryonic stage. Previous reports generally centered on the rational utilization of the in situ generated H-source (electrons) for hydrogenations, in which photogenerated holes were quenched by sacrificial reagents. Herein, the fully-utilization of the liquid H-source and holes during water splitting is presented for photo-reductive N-alkylation of nitro-aromatic compounds. In this integrate system, H-species in situ generated from water splitting were designed for nitroarenes reduction to produce amines, while alkanols were oxidized by holes for cascade alkylating of anilines as well as the generated secondary amines. More than 50 examples achieved with a broad range scope validate the universal applicability of this mild and sustainable coupling approach. The synthetic utility of this protocol was further demonstrated by the synthesis of existing pharmaceuticals via selective N-alkylation of amines. This strategy based on the sustainable water splitting technology highlights a significant and promising route for selective synthesis of valuable N-alkylated fine chemicals and pharmaceuticals from nitroarenes and amines with water and alkanols.
Asymmetric Cycloisomerization of o-Alkenyl-N-Methylanilines to Indolines by Iridium-Catalyzed C(sp3)?H Addition to Carbon–Carbon Double Bonds
Torigoe, Takeru,Ohmura, Toshimichi,Suginome, Michinori
supporting information, p. 14272 - 14276 (2017/10/23)
Highly enantioselective cycloisomerization of N-methylanilines, bearing o-alkenyl groups, into indolines is established. An iridium catalyst bearing a bidentate chiral diphosphine effectively promotes the intramolecular addition of the C(sp3)?H bond across a carbon–carbon double bond in a highly enantioselective fashion. The reaction gives indolines bearing a quaternary stereogenic carbon center at the 3-position. The reaction mechanism involves rate-determining oxidative addition of the N-methyl C?H bond, followed by intramolecular carboiridation and subsequent reductive elimination.
Convenient method for the 3-functionalization of isoindazoles
Bunnell, Aaron,O'Yang, Counde,Petrica, Andra,Soth, Michael J.
, p. 285 - 293 (2007/10/03)
The C-3 position of isoindazoles is readily functionalized by metalation with lithium diisopropylamide followed by reaction with a variety of electrophiles. Copyright Taylor & Francis LLC.
A practical synthesis of highly functionalized aryl nitriles through cyanation of aryl bromides employing heterogeneous Pd/C
Hatsuda, Masanori,Seki, Masahiko
, p. 1849 - 1853 (2007/10/03)
An industrially viable cyanation of aryl bromides with Zn(CN)2 was accomplished in the presence of inexpensive and readily accessible Pd/C, Zn dust, ZnBr2, and PPh3 in DMA to provide functionalized aryl nitriles in moderate to high yields.
A practical synthesis of highly functionalized aryl nitriles through cyanation of aryl bromides employing heterogeneous Pd/C: In quest of an industrially viable process
Hatsuda, Masanori,Seki, Masahiko
, p. 9908 - 9917 (2007/10/03)
Preparation of aryl nitrile 2a through classical Rosenmund-von Braun reaction of aryl bromide 1a resulted in a poor yield (61%) due to a high reaction temperature (165°C) and a lack of efficient procedure for separating 2a from a large quantity of heavy metal waste (Cu salts). To address these issues, a practical synthesis of multifunctional aryl nitriles through cyanation of aryl bromides has been developed with heterogeneous Pd/C used as the catalyst. Treatment of aryl bromides 1 with Zn(CN)2 in the presence of Pd/C, Zn, ZnBr2 and PPh3 in DMA provided aryl nitriles 2 involving those carrying sterically demanding electron-rich substituent in good yields and in highly reproducible manner. The activity of Pd/C is highly dependent on the properties of the Pd/C. Oxidic thickshell type catalyst Pd/C D5 was found to furnish the highest rate acceleration and yield. The use of heterogeneous Pd/C might anchor and disperse Pd over the solid support of the catalyst, at least in the initial stage of the reaction, to assure the formation of monomeric Pd complex without precipitating to inactive Pd black. The use of a slightly excess of Zn(CN)2 (0.6 equiv) and air oxidation of phosphine ligand, after end of the reaction, converted Pd species to insoluble phosphine-free Pd cyanides, from which Pd was recovered in high yield through simple filtration followed by usual recovery process involving combustion.
Copper-catalyzed domino halide exchange-cyanation of aryl bromides
Zanon, Jacopo,Klapars, Artis,Buchwald, Stephen L.
, p. 2890 - 2891 (2007/10/03)
An efficient copper-catalyzed domino halogen exchange-cyanation procedure for aryl bromides was developed utilizing 10 mol % CuI, 20 mol % KI, 1.0 equiv of the inexpensive N,N′-dimethylethylenediamine as ligand, and 1.2 equiv of NaCN in toluene at 110 °C. The new method represents a significant improvement over the traditional Rosenmund-von Braun reaction: the reaction conditions are much milder, and the use of stoichiometric amounts of copper(I) cyanide and polar solvents is avoided; therefore the isolation and purification of the aromatic nitrile products is greatly simplified. In addition, the new method exhibits excellent functional group compatibility comparable to that of the analogous Pd-catalyzed cyanation methodology. Copyright
Unusual aminations with tetramethylguanidine
Gabbutt, Christopher D.,Heron, B. Mark,McCreary, Janice M.,Thomas, David A.
, p. 69 - 71 (2007/10/03)
Heating activated halobenzenes with 1,1,3,3-tetramethylguanidine affords mixtures of dimethylaminobenzenes and 2-aryl-1,1,3,3-tetramethylguanidines.
Synthesis of heteroarenecarbonitriles by electrophilic cyanation; Reaction of metalated heteroarenes with p-toluenesulfonyl cyanide
Nagasaki, Izuru,Suzuki, Yumiko,Iwamoto, Ken-Ichi,Higashino, Takeo,Miyashita, Akira
, p. 443 - 450 (2007/10/03)
Several heteroarenecarbonitriles (5) were synthesized in moderate yields from heteroarenes (3) through metalation, followed by electrophilic cyanation using p-toluenesulfonyl cyanide. Similarly, trimethylsilylheteroarenes (8) were converted to heteroarenecarbonitriles (5) in good yields by treatment with p-toluenesulfonyl cyanide.
