Zobrazeno 1 - 10
of 28
pro vyhledávání: '"Yanqiao Xiang"'
Autor:
Yanqiao Xiang, David A. Foley, Jian Wang, George L. Reid, Brent J. Maranzano, Brian L. Marquez, Mark T. Zell
Publikováno v:
Analytical Chemistry. 85:8928-8932
Detector response is not always equivalent between detectors or instrument types. Factors that impact detector response include molecular structure and detection wavelength. In liquid chromatography (LC), ultraviolet (UV) is often the primary detecto
Publikováno v:
Journal of Chromatography A. 1293:150-158
Nine amide derivatives bearing α-stereocenters as well as different substitutions on the amide nitrogen were synthesized via an n-propanephosphonic acid cyclic anhydride (T3P)-mediated coupling, and their enantiomeric pairs were separated using supe
Autor:
Cheryl Myers Hayward, Brian T. O’Neil, Yanqiao Xiang, John VanAlsten, Daniel W. Widlicka, John C. Murray, Pfisterer David Michael, Steven J. Boucher, Joseph Michael Young, Lacey Samp, Bryan Li, John C. Lucas
Publikováno v:
Organic Process Research & Development. 16:2031-2035
N-Aryl pyrazoles were prepared from anilines in a three step telescoped approach. An aniline was diazotized to give the diazonium fluoroborate, followed by reduction with tin(II) chloride to give the corresponding hydrazine, which in turn reacted wit
General and Scalable Amide Bond Formation with Epimerization-Prone Substrates Using T3P and Pyridine
Publikováno v:
Organic Letters. 13:5048-5051
The mild combination of T3P (n-propanephosphonic acid anhydride) and pyridine has been developed for low-epimerization amide bond formation and implemented for the synthesis of a key intermediate to a glucokinase activator. This robust method is gene
Autor:
Yanqiao Xiang, Gregory W. Sluggett
Publikováno v:
Journal of Pharmaceutical and Biomedical Analysis. 53:878-883
Enantioselective HPLC, SFC and GC methods were evaluated for separation and quantitative determination of chiral purity of (2R,4R)-1-(1-tert-butoxyvinyl)-4-methoxypyrrolidine-2-carboxylic acid [(2R,4R)-TBMPCA], a common building block in organic synt
Autor:
Yanqiao Xiang, Peter G. M. Wuts, Ben Hritzko, Scott W. Ashford, Bill Taylor, Peter S. Zakarias, Brian G. Conway, Havens Jeffrey L
Publikováno v:
Organic Process Research & Development. 13:331-335
This contribution describes a scalable synthesis of the INOS inhibitor PHA-399733 using the Bucherer−Bergs hydantoin synthesis to introduce the amino acid function.
Publikováno v:
Organic Process Research & Development. 12:116-119
Many metal-mediated cross-couplings involve the use of organic halides, which are usually accessed by halogenation reactions. Cross-couplings are sensitive to the presence of impurities in the hali...
Autor:
Guoping Xue, Hian Kee Lee, Jerald S. Bradshaw, Yinhan Gong, M.L. Lee, Bingfang Yue, Yanqiao Xiang
Publikováno v:
Journal of Chromatography A. 1002:63-70
Two bonded chiral stationary phases (CSPs), 8-aminoquinoline-2-ylmethyl- and 8-aminoquinoline-7-ylmethyl-diaza-18-crown-6-capped [3-(2-O-beta-cyclodextrin)-2-hydroxypropoxy]propylsilyl silica particles (non-porous, 1.5 microm), have been prepared and
Publikováno v:
Journal of Chromatography A. 991:189-196
Ultrahigh pressure liquid chromatography (UHPLC) is an emerging technique which utilizes pressures higher than 10,000 p.s.i. to overcome the flow resistance imposed when using very small particles as packing materials in fused-silica capillary column
Publikováno v:
Journal of Chromatography A. 983:83-89
Capillary columns packed with small diameter particles typically lead to low permeability and long separation times in high-performance liquid chromatography. Ultrahigh pressures (10,000 p.s.i.; 1 p.s.i. is identical with 6,894.76 Pa) can be used to