25287-39-2Relevant academic research and scientific papers
Chiral N-heterocyclic carbene-iridium complexes for asymmetric reduction of prochiral ketimines
Kathuria, Lakshay,Samuelson, Ashoka G.
, (2020/12/28)
Enantioselective reduction of imines to the corresponding chiral secondary amines has been studied using a series of chiral half-sandwich iridium complexes. Chiral N-heterocyclic carbene (NHC) ligands in these complexes were synthesized from readily available, naturally occurring amino acids. Inexpensive phenylsilane was used as a convenient hydrogen donor. Under the optimized conditions, Ir-NHC complexes could reduce ketimines in good yields, albeit with moderate enantiomeric excess (ee). The phenylglycine derived chiral NHC was shown to give the best Ir catalyst and it also gave the maximum ee compared to catalysts prepared from other NHCs in this series. The opposite enantiomer of the reduction product was always obtained while using the Ir complex bearing a valine based NHC. The yields were consistently high with a variety of imine substrates having different steric and electronic demands.
Transition-Metal-Free Addition of Acetylenes to Ketimines: the First Base-Catalyzed Ethynylation of the C=N Bond
Bidusenko, Ivan A.,Schmidt, Elena Yu.,Ushakov, Igor A.,Trofimov, Boris A.
supporting information, p. 4845 - 4849 (2018/09/14)
A one-pot transition metal-free synthesis of propargylamines in good to excellent yield from ketone-derived imines and aryl- and hetarylacetylenes in the presence of KOBut/DMSO superbase system (40 °C, 10 min) has been developed. The reaction i
Decrypting Transition States by Light: Photoisomerization as a Mechanistic Tool in Br?nsted Acid Catalysis
Renzi, Polyssena,Hioe, Johnny,Gschwind, Ruth M.
supporting information, p. 6752 - 6760 (2017/05/29)
Despite the wide applicability of enantioselective Br?nsted acid catalysis, experimental insight into transition states is very rare, and most of the mechanistic knowledge is gained by theoretical calculations. Here, we present an alternative approach (de
“Half-sandwich” Schiff-base Ir(III) complexes as anticancer agents
Mou, Ze-dong,Deng, Ning,Zhang, Feng,Zhang, Jiaying,Cen, Juan,Zhang, Xia
, p. 72 - 82 (2017/06/27)
A series of “half-sandwich” Schiff-base Ir(III) complexes were synthesized and investigated for their in vitro activities against the leukemia K562 cell line. These compounds demonstrated antiproliferative activities against K562 cells with IC50 values of 0.26–4.77 μM. In particular, compound 10c showed cytotoxicity against five cancer cell lines/sublines and stronger activities than cisplatin in K562, K562/A02, MCF-7, MCF-7/ADM, and A549 cells. Mechanism studies illustrated that compound 10c increased the level of reactive oxygen species and induced apoptosis of K562 cells. This compound effectively decreased the mitochondrial membrane potential and the protein level of Bcl-2. It also increased the protein levels of Bax, caspase-3, and caspase-9, and led to release of cytochrome c in K562 cells, indicating that the apoptosis induced by compound 10c was mediated by the intrinsic mitochondria apoptosis pathway.
Palladium-catalyzed aerobic oxidative hydroamination of vinylarenes using anilines: A wacker-type amination pathway
Song, Eunsun,Kim, Hun Young,Oh, Kyungsoo
supporting information, p. 5264 - 5267 (2017/11/06)
A palladium-catalyzed intermolecular hydroamination of vinylarene derivatives using anilines has been developed for the first time under aerobic conditions, where the regioselective formation of N-arylketimines is accomplished. The current aerobic oxidative hydroamination pathway of anilines is distinct from that of palladiumcatalyzed hydroamination reactions that proceed to give sec-arylethylamine and arylethylamine derivatives, identifying a longstanding missing reaction pathway, Wacker-type amination, to N-arylketimines using anilines. The ready availability of both starting materials, vinylarenes and anilines, offers an attractive and facile synthetic route to N-arylketimines in good to excellent yields.
Sulfinamide Phosphinates as Chiral Catalysts for the Enantioselective Organocatalytic Reduction of Imines
Chelouan, Ahmed,Recio, Rocío,Borrego, Lorenzo G.,álvarez, Eleuterio,Khiar, Noureddine,Fernández, Inmaculada
supporting information, p. 3258 - 3261 (2016/07/14)
A new type of chiral sulfinamide phosphinate catalysts with up to three stereogenic centers, readily accessible from commercially available starting materials, is reported. The naphthyl derivative SulPhos proved to be highly efficient in the organocatalyt
A Frustrated Lewis Pair Catalyzed Asymmetric Transfer Hydrogenation of Imines Using Ammonia Borane
Li, Songlei,Li, Gen,Meng, Wei,Du, Haifeng
supporting information, p. 12956 - 12962 (2016/10/13)
Inspired by the zwitterion species generated from the splitting of H2 by frustrated Lewis pairs, we put forward a novel frustrated Lewis pair by the combination of Hδ and Hδ incorporated Lewis acid and base together. Piers
Facile synthesis of 4- and 7-azaindoles from the corresponding imines by palladium-catalyzed cascade C-C and C-N coupling
Pham, Ngo Nghia,Dang, Thanh Tuan,Ngo, Ngoc Thang,Villinger, Alexander,Ehlers, Peter,Langer, Peter
supporting information, p. 6047 - 6058 (2015/06/08)
The cyclization of 2,3-dihalopyridines with readily available imines provides a convenient and regioselective approach to 4- and 7-azaindoles. The regioselectivity can be controlled by the choice of the halogen atoms at the pyridine ring (chlorine versus
Ruthenium-catalyzed reductive methylation of imines using carbon dioxide and molecular hydrogen
Beydoun, Kassem,Ghattas, Ghazi,Thenert, Katharina,Klankermayer, Jürgen,Leitner, Walter
supporting information, p. 11010 - 11014 (2015/03/30)
The use of the well-defined [Ru(triphos)(tmm)] catalyst, CO2 as C1 source, and H2 as reducing agent enabled the reductive methylation of isolated imines, as well as the direct coupling of amines with aldehydes and the subsequent reductive methylation of the insitu formed imines. The method, which afforded the corresponding N-methyl amines in very good to excellent yields, was also used for the preparation of the antifungal agent butenafine in one step with no apparent waste, thus increasing the atom efficiency of its synthesis.
Primary amines by transfer hydrogenative reductive amination of ketones by using cyclometalated IrIII catalysts
Talwar, Dinesh,Salguero, Noemi Poyatos,Robertson, Craig M.,Xiao, Jianliang
supporting information, p. 245 - 252 (2014/01/17)
Cyclometalated iridium complexes are found to be versatile catalysts for the direct reductive amination (DRA) of carbonyls to give primary amines under transfer-hydrogenation conditions with ammonium formate as both the nitrogen and hydrogen source. These complexes are easy to synthesise and their ligands can be easily tuned. The activity and chemoselectivity of the catalyst towards primary amines is excellent, with a substrate to catalyst ratio (S/C) of 1000 being feasible. Both aromatic and aliphatic primary amines were obtained in high yields. Moreover, a first example of homogeneously catalysed transfer-hydrogenative DRA has been realised for β-keto ethers, leading to the corresponding β-amino ethers. In addition, non-natural α-amino acids could also be obtained in excellent yields with this method. Reduce the work! A broad range of ketones have been successfully aminated to afford primary amines under transfer-hydrogenation conditions by using ammonium formate as the amine source and 0.1 mol % of a cyclometalated IrIII catalyst (see scheme). Copyright
