- A Commercially Available and User-Friendly Catalyst for Hydroamination Reactions under Technical Conditions
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The activity of a simple, commercially available copper salt, [Cu(NCMe)4](BF4) in intramolecular hydroamination reactions of alkynes and allenes is presented. Reactions were successfully carried out in technical acetonitrile in the presence of air. While attempts of alkene hydroamination failed, this catalyst was also found active in intermolecular aza-Michael reactions.
- Zelenay, Benjamin,Munton, Peter,Tian, Xiaojie,Díez-González, Silvia
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p. 4725 - 4730
(2019/08/01)
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- Facile one-pot synthesis of 2,3-dihydro-1H-indolizinium derivatives by rhodium(iii)-catalyzed intramolecular oxidative annulation via C-H activation: application to ficuseptine synthesis
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Various substituted indolizidinium, quinolizinium and pyrido[1,2-a]azepinium salts synthesized from benzaldehydes (or α,β-unsaturated aldehydes) and alkyne-amines catalyzed by rhodium complexes via C-H activation are demonstrated. The reaction was carried
- Upadhyay, Nitinkumar Satyadev,Jayakumar, Jayachandran,Cheng, Chien-Hong
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p. 2491 - 2494
(2017/03/01)
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- Constrained geometry organoactinides as versatile catalysts for the intramolecular hydroamination/cyclization of primary and secondary amines having diverse tethered C-C unsaturation
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A series of "constrained geometry" organoactinide complexes, (CGC)An(NMe)2 (CGC = Me2-Si(η5-Me 4C5)(tBuN); An = Th, 1; U, 2), has been prepared via efficient in situ, two-step protodeamination routes in good yields and high purity. Both 1 and 2 are quantitatively converted to the neutrally charged, solvent-free dichlorides (1-Cl2, 2-Cl2) and slightly more soluble diiodides (1-I2, 2-I2) with excess Me3Si-X (X = Cl, I) in non-coordinating solvents. The new complexes were characterized by NMR spectroscopy, elemental analysis, and (for 1 and 2) single-crystal X-ray diffraction, revealing substantially increased metal coordinative unsaturation vs the corresponding Me2SiCp″ 2AnR2 (Cp″ = η5-Me4C 5; An = Th, R = CH2-(SiMe3), 3; An = U, R = CH2Ph, 4) and Cp′2AnR2 (Cp′ = η5-Me5C5 ; An = Th, R = CH 2(SiMe3), 5; An = U, R = CH2(SiMe3), 6) complexes. Complexes 1-6 exhibit broad applicability for the intramolecular hydroamination of diverse C-C unsaturations, including terminal and internal aminoalkenes (primary and secondary amines), aminoalkynes (primary and secondary amines), aminoallenes, and aminodienes. Large turnover frequencies (N t up to 3000 h-1) and high regioselectivities (≥95%) are observed throughout, along with moderate to high diastereoselectivities (up to 90% trans ring closures). With several noteworthy exceptions, reactivity trends track relative 5f ionic radii and ancillary ligand coordinative unsaturation. Reactivity patterns and activation parameters are consistent with a reaction pathway proceeding via turnover-limiting C=C/C=C insertion into the An-N σ-bond.
- Stubbert, Bryan D.,Marks, Tobin J.
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p. 4253 - 4271
(2008/02/01)
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- Intramolecular hydroamination of alkynes catalyzed by Pd(PPh 3)4/triphenylphosphine under neutral conditions
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The intramolecular hydroamination of alkynes tethered with amino group 1 in the presence of catalytic amounts of Pd(PPh3)4 and PPh3 in benzene at 100°C proceeded smoothly without the use of any additional acid source to af
- Bajracharya, Gan B.,Huo, Zhibao,Yamamoto, Yoshinori
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p. 4883 - 4886
(2007/10/03)
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- Cyanoguanidines as cell proliferation inhibitors
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The present invention relates to hitherto unknown compounds of formula (I) or their tautomeric forms, the attachment to the pyridine being in the 3- or 4-position, in which formula R1 stands for one or more substituents which can be the same or different and are selected from the group consisting of: hydrogen, halogen, trifluoromethyl nitro, amino, cyano, carboxy, or alkyl, alkoxy, or alkoxycarbonyl, the C-content of which can be from 1 to 4; X stands for a straight or branched C9-C20 carbon chain, saturated or unsaturated or Q—Ar—R; in which formula Ar stands for phenyl, Q stands for a C5-C20 divalent hydrocarbon radical which can be straight, branched, saturated or unsaturated and R stands for hydrogen or for one or more substituents which can be the same or different and are selected from the group consisting of: hydroxy, amino, halogen, trifluoromethyl, cyano, nitro, carboxy, carbamoyl, or alkyl, alkoxy, alkylthio, alkylamino, or alkoxycarbonyl, the C-content of which can be from 1 to 4; and pharmaceutically acceptable, non-toxic salts and N-oxides thereof. The present compounds are of value in the human and veterinary practice.
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- Organolanthanide-catalyzed intramolecular hydroamination/cyclization of aminoalkynes
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This contribution reports the efficient and regiospecific Cp'2LnCH(SiMe3)2 (Ln = La, Nd, Sm, Lu; Cp' = η5-Me5C5)- and Me2SiCp''2LnCH(SiMe3)2 (Ln = Nd, Sm; Cp'' = η5-Me4C5)-catalyzed hydroamination/cyclization of aliphatic and aromatic aminoalkynes of the formula RC≡C(CH2)(n)NH2 to yield the corresponding cyclic imines RCH2C=N(CH2)(n-1)CH2, where R, n, N(t) h-1 (°C) = Ph, 3, 77 (21°C); Ph, 3, 2830 (60°C); Me, 3, 96 (21°C); CH2=CMeCH2, 3, 20 (21°C); H, 3, 580 (21°C); Ph, 4, 4 (21°C); Ph, 4, 328 (60°C); Ph, 5, 0.11 (60°C); and SiMe3, 3, >7600 (21°C), and of aliphatic secondary amino-alkynes of the formula RC≡C(CH2)3NHR1 to generate the corresponding cyclic enamines RCH=CNR1(CH2)2CH2 where R, R1, N(t) h-1 (°C) = SiMe3, CH2=CHCH2, 56 (21°C); H, CH2=CHCH2, 27 (21°C); SiMe3, CH2=CH(CH2)3, 129 (21°C); and H, CH2=CH(CH2)3, 47 (21°C). Kinetic and mechanistic evidence is presented arguing that the turnover-limiting step is an intramolecular alkyne insertion into the Ln-N bond followed by rapid protonolysis of the resulting Ln-C bond. The use of larger metal ionic radius Cp'2LnCH(SiMe3)2 and more open Me2SiCp''2LnCH(SiMe3)2 complexes as the precatalysts results in a decrease in the rate of hydroamination/cyclization, arguing that the steric demands in the -C≡C- insertive transition state are relaxed compared to those of the analogous aminoolefin hydroamination/cyclization.
- Li,Marks
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p. 9295 - 9306
(2007/10/03)
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- Preparation of 2,3,4,5-tetrahydropyridines from 5-alkynylamines under the catalytic action of gold(III) salts
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Intramolecular addition of amine to carbon-carbon triple bonds in 5-alkynylamines produces 2,3,4,5-tetrahydropyridines under the catalytic action of an aurate salt. Some venom components of various ant species are synthesized by the application of this re
- Fukuda,Utimoto
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p. 975 - 978
(2007/10/02)
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- Palladium-Catalyzed Intramolecular Addition of Amines to Acetylenes. Synthesis of Cyclic Imines
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Intramolecular aminopalladation of alkynylamines gave intermediary alkenylpalladium compounds that hydrolyzed and isomerized to thermodynamically stable cyclic imines.Treatment of 3-alkynylamines with a catalytic amount of PdCl2(MeCN)2 gave exclusively 1-
- Fukuda, Yukitoshi,Matsubara, Seijiro,Utimoto, Kiitiro
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p. 5812 - 5816
(2007/10/02)
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