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Gel-phase 13C NMR spectroscopy

Thus, the latter approach was clearly preferable and several NPG donors were coupled to 41 under these conditions in order to investigate trends in anomeric selectivity, as monitored by gel-phase 13C NMR spectroscopy (Table 5.1).66 As expected, neighboring-group active donors 44 and 45 produced solely the... [Pg.109]

Natural abundance gel-phase 13C NMR spectroscopy is used for assessing intermediate structures in solid-phase synthesis [20], but requires long acquisition times and so is not useful for following reactions. Affymax scientists [21] have pioneered the use of specifically 13C-labeled starting materials in conjunction with fast 13C-gel phase NMR to follow multi-step reactions [17,22,23],... [Pg.61]

R Epton, P Goddard, KJ Ivin. Gel phase 13C NMR spectroscopy as an analytical method in solid (gel) phase peptide synthesis. Polymer 21 1367-1371, 1980. [Pg.106]

Brandstetter, M. (2009). Ultrasonically enhanced in-line Attenuated Total Reflection (ATR) infrared absorption spectroscopy of suspensions. Diploma Thesis, Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna Braunshier, C. Hametner, C. Froehlich, J. Schnoeller, J. Hutter, H. (2008). Novel monodisperse PEG-grafted polystyrene resins synthesis and application in gel-phase 13C NMR spectroscopy. Tetrahedron Letters Vol.49, pp. 7103-7105, ISSN 0040-4039... [Pg.508]

Notwithstanding all its advantages, the principle of solid-phase synthesis cannot be applied to all kinds of chemical reactions. Although reactants are used in excess, reaction is not always quantitative. The resulting impurities cannot be separated on the solid phase, giving rise to separation problems particularly in multi-step systems. Moreover, only limited use can often be made of conventional analytical methods (NMR, MS). Recent methods of 13C-NMR spectroscopy on solid phases [21] or in gel phases [22] are ideally suited for solid-phase synthesis, but are not universally available owing to the expensive instrumentation. [Pg.32]

C gel-phase NMR spectroscopy, because of smaller line widths and better chemical shift dispersion of the 13C lines, is a reliable technique to determine the success or failure of chemical transformations. However, as a consequence of the low sensitivity of the... [Pg.533]


See other pages where Gel-phase 13C NMR spectroscopy is mentioned: [Pg.82]    [Pg.82]    [Pg.167]    [Pg.32]    [Pg.138]    [Pg.127]    [Pg.25]    [Pg.75]    [Pg.291]    [Pg.35]   
See also in sourсe #XX -- [ Pg.109 , Pg.167 , Pg.291 ]

See also in sourсe #XX -- [ Pg.42 ]




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