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101.
A methodology for the formal addition of β-acylalkenyl anions was developed by utilizing the [1,2]-phospha-Brook rearrangement under Brønsted base catalysis. The two-step reaction involves the catalytic addition of α-oxygenated propargyl anions generated via [1,2]-phospha-Brook rearrangement to electron-deficient ketones and subsequent alcoholysis to afford tertiary alcohols having an enone moiety. This is a rare example of a catalytic carbon-carbon bond forming reaction of β-acylalkenyl anion equivalents, providing synthetic building blocks that are otherwise difficult to access.  相似文献   
102.
Intermolecular radical thiophosphination of terminal alkynes with alkylthio- and arylthiophosphines affords 1-thio-2-phosphino-1-alkenes in good yields. The addition reaction proceeds predominantly in an anti fashion to yield E isomers.  相似文献   
103.
The formal synthesis of (+)-laurallene, a halogenated eight-membered ring ether, was accomplished. The synthesis involves construction of a trans alpha,alpha'-disubstituted oxocene structure 16 through a Brook rearrangement-mediated [3+4] annulation using acryloylsilane 10 and 6-oxa-2-cycloheptenone 9 and its conversion into 2, which has been transformed into (+)-laurallene by Crimmins and co-workers.  相似文献   
104.
The photoreaction of tetrakis(2-methylthien-3-yl)ethene (1a) and its tetrakis(methylthio) derivative 1b was investigated in the context of a potentially new chromic system responsive to both photoexcitation and electron transfer. UV irradiation of 1 at low conversion leads to production of its cyclic isomer 2 while 2 returns to 1 upon vis irradiation, representative of facile photochromic behavior. In contrast, UV irradiation at high conversion transforms 1b to rearranged product 3b via the intermediacy of 2b.  相似文献   
105.
Infrared photodissociation (IRPD) spectra of carbon dioxide cluster ions, (CO(2))(n) (+) with n=3-8, are measured in the 1000-3800 cm(-1) region. IR bands assignable to solvent CO(2) molecules are observed at positions close to the vibrational frequencies of neutral CO(2) [1290 and 1400 cm(-1) (nu(1) and 2nu(2)), 2350 cm(-1) (nu(3)), and 3610 and 3713 cm(-1) (nu(1)+nu(3) and 2nu(2)+nu(3))]. The ion core in (CO(2))(n) (+) shows several IR bands in the 1200-1350, 2100-2200, and 3250-3500 cm(-1) regions. On the basis of previous IR studies in solid Ne and quantum chemical calculations, these bands are ascribed to the C(2)O(4) (+) ion, which has a semicovalent bond between the CO(2) components. The number of the bands and the bandwidth of the IRPD spectra drastically change with an increase in the cluster size up to n=6, which is ascribed to the symmetry change of (CO(2))(n) (+) by the solvation of CO(2) molecules and a full occupation of the first solvation shell at n=6.  相似文献   
106.
A stacked donut-like mesospace is successfully introduced into Pt fibers by assembling Pt nanoparticles with uniform particle size, by utilizing the guided deposition of Pt nanoparticles in preferentially oriented liquid crystals. We clearly demonstrate that the collaboration of both LLC templating by electrochemical processes and hard templating utilizing a confined effect can lead to the genesis of new nanostructured metals. Such a unique metal-based nanoarchitecture enhances the surface area and enables the high-mass transportation of guest species. Preferentially oriented mesochannels should contribute significantly to the fine control and transport of electronic carriers through metal fibers.  相似文献   
107.
Nihei M  Ui M  Hoshino N  Oshio H 《Inorganic chemistry》2008,47(14):6106-6108
A building unit of Prussian blue was isolated as a cyanide-bridged iron cube of [Fe(II)4Fe(III)4(CN)12(tp)8] x 12 DMF x 2 Et2O x 4 H2O [tp(-) = hydrotris(pyrazolyl)borate]. A cyclic voltammogram showed quasi-reversible four-stepped redox waves, which correspond to [Fe(III)4Fe(II)4]/[Fe(III)5Fe(II)3](+), [Fe(III)5Fe(II)3](+)/[Fe(III)6Fe(II)2](2+), [Fe(III)6Fe(II)2](2+)/[Fe(III)7Fe(II)1](3+), and [Fe(III)7Fe(II)1](3+)/[Fe(III)8](4+) processes. Controlled potential absorption spectral measurements revealed two intervalence charge-transfer bands at 816 and 1000 nm, which were assigned to charge transfers from Fe(II) ions to adjacent and remote Fe(III) ions, respectively, in the cube.  相似文献   
108.
The hexadentate nitrogen ligands 1-isoTQEN ( N,N,N',N'-tetrakis(1-isoquinolylmethyl)ethylenediamine) and 3-isoTQEN ( N,N,N',N'-tetrakis(3-isoquinolylmethyl)ethylenediamine) have been prepared. The structures of these ligands are based on that of TPEN ( N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine). The introduction of a benzene ring into TPEN affords fluorescence ability upon zinc-ion binding. Compared to the quinoline isomer TQEN, isoquinoline derivatives 1-isoTQEN and 3-isoTQEN exhibit a lower-energy shift in the excitation and emission wavelengths and an enhanced fluorescence intensity, probably because of the energy-transfer mechanism between adjacent isoquinoline rings. Importantly, an increase in the Zn (2+)/Cd (2+) discriminating ability and a reduction in the background fluorescence induced by pH were also achieved for isoquinoline derivatives. The zinc-ion-induced fluorescence of these isoTQENs was not quenched by an addition of TPEN, which demonstrates the significantly high zinc-ion binding ability of these isoTQEN ligands.  相似文献   
109.
Treatment of alkyne with alkanethiol in the presence of a catalytic amount of cesium carbonate and a radical inhibitor in DMSO provides the corresponding adduct, (Z)-1-alkenyl alkyl sulfide, in good yield with high selectivity.  相似文献   
110.
Reactions of a quadridentate ligand [N-(2-hydroxy-5-nitrobenzyl)iminodiethanol] with iron and manganese chloride in methanol yielded an antiferromagnetic FeIII6 ring and a single-molecule magnet MnII3MnIII4 wheel, respectively.  相似文献   
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