33611-54-0Relevant academic research and scientific papers
Light-Driven Enantioselective Synthesis of Pyrroline Derivatives by a Radical/Polar Cascade Reaction
Rodríguez, Ricardo I.,Mollari, Leonardo,Alemán, José
supporting information, p. 4555 - 4560 (2021/01/18)
Herein, a light-driven, atom-economical process that provides access to enantiomerically enriched substituted chiral 1-pyrroline derivatives is introduced. The strategy involves the distal functionalization of acyl heterocycles through a hydrogen-atom transfer (HAT) process and the use of tailor-made ketimines as reliable electrophilic partners. This transformation is translated into an enantiomerically controlled radical/polar cascade reaction in which water is produced as the sole by-product and stereoselectivity is dictated by coordination to a chiral-at-rhodium catalyst.
Cobalt-Catalyzed, N-H Imine-Directed Arene C-H Benzylation with Benzyl Phosphates
Laskar, Roshayed Ali,Yoshikai, Naohiko
, p. 13172 - 13178 (2019/09/10)
A cobalt-catalyzed ortho-C-H benzylation reaction of pivalophenone N-H imines with benzyl phosphates is reported. The reaction is promoted at room temperature by a ternary catalytic system comprising Co(acac)3, a pyridylphosphine ligand, and a Grignard reagent and tolerates a series of substituted pivalophenone imines and benzyl phosphates to afford various diarylmethane derivatives in moderate yields.
AMINATION AND HYDROXYLATION OF ARYLMETAL COMPOUNDS
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Paragraph 0098; 0130; 0131, (2018/03/25)
In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.
Radical and Nitrenoid Reactivity of 3-Halo-3-phenyldiazirines
Navrátil, Rafael,Tarábek, Ján,Linhart, Igor,Martin?, Tomá?
supporting information, p. 3734 - 3737 (2016/08/16)
3-Halo-3-phenyl-3H-diazirines (halogen = Br or Cl) undergo a dissociative single-electron transfer from alkyllithiums (RLi) in THF-based solvent mixtures. The resulting 3-phenyldiazirinyl radical, observed by EPR spectroscopy, is eventually transformed to benzonitrile. In Et2O, 2 equiv of RLi add to both nitrogens of halodiazirine N=N bond, affording N,N′-dialkylbenzamidines. The nitrenoid reactivity of some N-alkyl-1H-diazirine intermediates is manifested by their insertion into the α-C-H bond of THF or Et2O.
An evaluation of substituent effects on aromatic edge-to-face interactions and CF-π versus CH-π interactions using an imino torsion balance model
Jennings, W. Brian,O'Connell, Niamh,Malone, John F.,Boyd, Derek R.
, p. 5278 - 5291 (2013/08/23)
A selection of imines derived from phenyl t-butyl ketones and substituted 2-phenylethylamines or phenylalanine exhibit slow rotation around the aryl-imino bond at ambient temperature, resulting in a large non-equivalence of the ortho hydrogens in the 1H NMR spectra. This facilitates assessment of aryl substituent effects on the face tilted-T CH-π interaction between a phenyl ring (A) on the imino carbon proximate to the terminal phenyl ring (B). Analysis of the marked temperature dependence of the chemical shift of the interacting ortho hydrogen affords estimates of the opposing enthalpic and entropic factors involved in the rapid equilibrium between the closed edge-to-face conformation and alternative open conformations devoid of a CH-π interaction while in solution. Above ca. 80 °C the entropy term (TΔS) cancels out the enthalpy (ΔH) favouring the closed conformation and open conformations are preferred. Accordingly, commonly reported binding free energies may not be a good measure of the energetic strength of intramolecular aromatic interactions. Investigation of an ortho fluoro substituted compound indicates that a CF-π interaction is at least 1.0 kcal mol-1 weaker in enthalpy than the CH-π interaction. Several X-ray crystal structures depicting an intramolecular edge-to-face interaction are presented.
New stable N-H oxaziridines - Synthesis and reactivity
Blanc, Sylvain,Bordogna, Celine A. C.,Buckley, Benjamin R.,Elsegood, Mark R. J.,Bulman Page, Philip C.
supporting information; experimental part, p. 882 - 889 (2010/04/05)
A number of stable new N-H oxaziridines have been designed and prepared, and their reactivity as electrophilic sources of nitrogen investigated. 3-tert-Butyl-3-phenyloxaz-ridine is the most efficient and stable and has potential for use as a general reagent for this purpose.
2-Azaallenium Salts from N-Benzylidene-α-methoxybenzylamines
Weidner, Reinhold,Wuerthwein, Ernst-Ulrich
, p. 1095 - 1106 (2007/10/02)
New phenyl-substituted 2-azaallenium salts 1 with variable substitution pattern were synthesized in high yields and under mild reaction conditions by treatment of N-benzylidene-α-methoxy-benzylamines 4 with acylium salts.The amines 4 are easily accessible from imines 2 and α-chloro ethers 3 or from 2,4-diaza-1,4-pentadiones 7; only in the case of strong steric hindrance an alternate reaction (forming imidazole 6) takes place.Some of the new 2-azaallenium salts (1ea-1ed, 1fa-1fd) show high tendency for intramolecular cyclisation reactions leading to isoquinoline derivatives 8 and 9. - The structures of the salts 1 in solution were analysed on the basis of 1H- and 13C-NMR spectra with respect to the dynamic behaviour of the cations.For 1aa-1j cumulene structures were derived, for the intensively coloured 1k, however, a 2-azaallyl cation structure of the aza-trimethine dyestuff type was found (IR data). - Keywords: 2-Azaallenium Salts; N-Benzylidene-α-methoxybenzylamines
N-Acyl- and N-Aryl-N'-alkylidenureas as Precursors of Isocyanates or Acylisocyanates
Schweim, Harald G.,Juergens, Sabine
, p. 844 - 850 (2007/10/02)
Derivatives of isocyanates or acylisocyanates were prepared by reactions with ketimines.Fragmentation reactions of the product were examined.
Copper (I)-Activated Addition of Grignard Reagents to Nitriles. Synthesis of Ketimines, Ketones, and Amines
Weiberth, Franz J.,Hall, Stan S.
, p. 3901 - 3904 (2007/10/02)
The nucleophilic addition of Grignard reagents to nitriles, especially when using sterically demanding components, is effectively catalyzed by copper(I) salts.Alkyl and aromatic nitriles and a selection of Grignard reagents were employed to prepare sterically hindered ketimines after addition, ketones after a tandem addition-hydrolysis procedure, and branched primary amines after a tandem addition-reduction sequence.
