- Metal-free C(sp2)-H functionalization of azoles: K2CO3/I2-mediated oxidation, imination, and amination
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The direct C2-H oxidation and imination of a wide variety of azoles was achieved by using a commercially available simple K2CO3/I2 reagent combination. The iodinated azole adduct, produced via the in situ generation of N-heterocyclic carbene, is the key intermediate for C2-H oxidation, imination, and amination of azoles. Significantly, these reactions proceed under mild conditions with high to excellent yields, are scalable to large quantity and exhibit a broad substrate scope. Interestingly, this direct C2-H imination method allowed us to access various pharmacologically active N6-alkyl or N6-aryl substituted benzimidazoquinazolinone scaffolds through intramolecular C-H imination in a sequential one-pot reaction.
- Das, Ranajit,Banerjee, Mainak,Rai, Rakesh Kumar,Karri, Ramesh,Roy, Gouriprasanna
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supporting information
p. 4243 - 4260
(2018/06/22)
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- Novel N-heterocyclic ylideneamine gold(i) complexes: Synthesis, characterisation and screening for antitumour and antimalarial activity
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Ylideneamine functionalised heterocyclic ligands, 1,3-dimethyl-1,3-dihydro- benzimidazol-2-ylideneamine (I), 3-methyl-3H-benzothiazol-2-ylideneamine (II) or 3,4-dimethyl-3H-thiazol-2-ylideneamine (III), were employed in the preparation of a series of both charged and neutral gold(i) complexes consisting either of a Au(C6F5) fragment (1-3), a [Au(PPh3)] + unit (4-6) or a [Au(NHC)]+ unit (7) coordinated to the imine nitrogen of the neutral ylideneamine ligand. These complexes were fully characterised by various techniques including X-ray diffraction. In addition, the antitumour and antimalarial potential of selected compounds were assessed in a preliminary study aimed at determining the medicinal value of such compounds. Complexation of the azol-2-ylideneamine ligands with [Au(PPh3)] + increases their antitumour as well as antimalarial activity.
- Coetzee, Jacorien,Cronje, Stephanie,Dobrzanska, Liliana,Raubenheimer, Helgard G.,Joone, Gisela,Nell, Margo J.,Hoppe, Heinrich C.
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experimental part
p. 1471 - 1483
(2011/03/16)
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- O-COORDINATED METAL CHELATES AND THEIR USE IN OPTICAL RECORDING MEDIA HAVING HIGH STORAGE CAPACITY
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The invention relates to novel o ptical recording materials that comprise specific and in some cases novel diketone enamines or metal chelates thereof and that have excellent recording and playback quality especially ata wavelength of 350-500 nm. The invention accordingly relates to an optical recording medium comprising a substrate, a recording layer and optionally a reflecting layer, wherein the recording layer comprises a compound of formula (I), wherein M is hydrogen, aluminium or, preferably, a transition metal, which may in addition be coordinated with one or more further ligands and/or, for balancing out an excess charge, where applicable, may have an electrostatic interaction with one or more further ions inside or outside the coordination sphere, but M in formulae (Ib) and (Ic) is not hydrogen, Q is C-H, N or C-R6, it being possible for the stereochernistry of the C=Q double bond to be either E or Z. For the exact definitions of R1 to R6 reference should be made to the description. Also claimed are the novel compounds, especially tetracoordinated chelates, and a process for the preparation thereof.
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Page/Page column 31-32
(2010/02/10)
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- o-Iodoxybenzoic Acid (IBX) as a Viable Reagent in the Manipulation of Nitrogen- and Sulfur-Containing Substrates: Scope, Generality, and Mechanism of IBX-Mediated Amine Oxidations and Dithiane Deprotections
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o-Iodoxybenzoic acid (IBX), a highly versatile hypervalent iodine(V) reagent, was found to efficiently mediate the dehydrogenation of amines in addition to facilitating the oxidative cleavage of dithioacetals and dithioketals. Through the development of relevant IBX-based protocols, a plethora of useful synthetic intermediates, including imines, oximes, ketones, and aromatic N-heterocycles, were found to be readily accessible under notably mild conditions. Further investigation of these transformations led to the elucidation of valuable mechanistic details, resulting in the conclusion that they proceed via ionic rather than single electron transfer (SET) pathways.
- Nicolaou,Mathison, Casey J. N.,Montagnon, Tamsyn
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p. 5192 - 5201
(2007/10/03)
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- SHORT INTERACTIONS BETWEEN HETEROCYCLIC SULFUR ATOMS AND THIOCARBONYL SULFUR OR CARBONYL OXYGEN ATOMS
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Short intramolecular S--S=C contacts in N-(2-thiazolylidene)benzenecarbothioamides (11 and 12), 0.60 Angstroem less than the corresponding separation predicted by Van der Waals radii, are accounted for by Coulombic interractions and 3d orbital participation as a result of electron delocalisation within each molecule.Similar considerations apply to S--O=C contacts, however short S--S intermolecular interactions between sulfides are due to the asymmetric electron distribution about the bonded sulfide atoms.
- Hudson, Robert F.,Wallis, John D.,Hansell, David P.
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p. 1933 - 1950
(2007/10/02)
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- Process for the manufacture of 2-amino-aryleno-thiazole compounds and of derivatives thereof N-substituted in the ring
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2-Amino-aryleno-thiazoles in which the amino group in 2-position can be substituted by aryl, alkyl and/or cycloalkyl, and 2-imino-aryleno-thiazolines substituted at the ring nitrogen by aryl, alkyl or cycloalkyl are produced by cyclization of arylthioureas carrying corresponding substituents at the respective nitrogen atom, using thionyl chloride as cyclization agent. The advantage of the improved process resides in that the amount of sulfur formed is very low and that the other by-products are easy to separate and can be used further. The thiazoles and thiazolines are obtained in a high yield and purity. They are valuable starting compounds, especially for the manufacture of dyestuffs.
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