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111.
A simple and convergent synthesis of 2,3-disubstituted indoles has been developed using a sequential Larock indole synthesis and silicon-based, cross-coupling reaction. Substituted 2-iodoanilines reacted with an alkynyldimethylsilyl tert-butyl ether to afford indole-2-silanols under the Larock heteroannulation conditions after hydrolysis. The corresponding sodium 2-indolylsilanolate salts successfully engaged in cross-coupling with aryl bromides and chlorides to afford multi-substituted indoles. The development of an alkynyldimethylsilyl tert-butyl ether as a masked silanol equivalent enabled a smooth heteroannulation process and the identification of a suitable catalyst/ligand combination provided for a facile cross-coupling reaction. 相似文献
112.
We prove that any (real or complex) analytic horizontally conformalsubmersion from a three-dimensional conformal manifold (M3,cM) to a two-dimensional conformal manifold (N2, cN) can be,locally, extended to a unique harmonic morphismfrom the (eaven)-space (H4, g) of (M3, cN) to (N2, cN). Moreover,any positive harmonic morphism with two-dimensional fibres from(H4, g) is obtained in this way. 相似文献
113.
Sachin S. Thanawala Ronald J. Baird Daniel G. Georgiev Gregory W. Auner 《Applied Surface Science》2008,254(16):5164-5169
Amorphous and crystalline iridium oxide thin films with potential use as coating materials for stimulation electrodes were studied. Characterization of these films by cyclic voltammetry and impedance spectroscopy has revealed a considerable decrease in impedance and an increase in charge capacity of iridium oxide thin films after an electrochemical activation process in 0.9% NaCl solution. The surface morphology of these films was studied by scanning electron microscopy. The two types of IrO2 films were also compared under conditions relevant to applications as stimulation electrodes. The results indicate that amorphous IrO2 films have significantly higher charge storage capacity and lower impedance than crystalline IrO2 films. This makes the amorphous films a preferable coating material for stimulation applications. 相似文献
114.
The development of the fast field and parabolic equation solutions to the wave equation has made it possible to solve for the combined effects of refraction in a layered atmosphere and the interaction of sound with a complex impedance ground surface. In many respects the numerical methods have advanced beyond our understanding of the basic phenomena. In an earlier study [J. Acoust. Soc. Am. 89, 107-114 (1991)], the residue series solution for upward refraction was investigated and provided insight into the nature of the interaction of refraction and ground reflection. In this paper results are presented of a similar normal mode solution for downward refraction above a complex impedance ground surface. This model is used to investigate when the surface wave is excited for downward refraction conditions and to develop criteria for the maximum range of cylindrical decay as a function of phase and magnitude of the ground impedance and the magnitude of the sound velocity gradient. 相似文献
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Iodination of selected 1-allyl- or 1-benzyl-cyclopropenes with electron-donating groups on the substituent leads to 2-iodo-1-iodomethyl-1 -vinyl or 1-arylcyclopropanes. 相似文献
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Abe K Abt I Ahn CJ Akagi T Ash WW Aston D Bacchetta N Baird KG Baltay C Band HR Barakat MB Baranko G Bardon O Barklow T Bazarko AO Ben-David R Benvenuti AC Bienz T Bilei GM Bisello D Blaylock G Bogart JR Bolton T Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Busza W Calcaterra A Caldwell DO Calloway D Camanzi B Carpinelli M Cassell R Castaldi R Castro A Cavalli-Sforza M Church E Cohn HO Coller JA Cook V Cotton R Cowan RF Coyne DG D'Oliveira A Damerell CJ Dasu S 《Physical review letters》1995,74(15):2890-2894
120.
Abe K Abt I Ahn CJ Akagi T Allen NJ Ash WW Aston D Baird KG Baltay C Band HR Barakat MB Baranko G Bardon O Barklow T Bazarko AO Ben-David R Benvenuti AC Bienz T Bilei GM Bisello D Blaylock G Bogart JR Bolton T Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Busza W Calcaterra A Caldwell DO Calloway D Camanzi B Carpinelli M Cassell R Castaldi R Castro A Cavalli-Sforza M Church E Cohn HO Coller JA Cook V Cotton R Cowan RF Coyne DG D'Oliveira A Damerell CJ Daoudi M 《Physical review D: Particles and fields》1995,52(9):4828-4838