synthesized in moderate yield from readily available omega-amino-H-phosphinates and aldehydes or ketones via an intramolecular Kabachnik-Fields reaction. The products are conformationallyrestricted phosphinic analogs of alpha-amino acids. The multigram-scale syntheses of the H2N(CH2)(n)PO2H2 phosphinic precursors (n = 1, 2, 3) and some derivatives are also described.
Amplifying the Sensitivity of Zinc(II) Responsive MRI Contrast Agents by Altering Water Exchange Rates
作者:Jing Yu、André F. Martins、Christian Preihs、Veronica Clavijo Jordan、Sara Chirayil、Piyu Zhao、Yunkou Wu、Khaled Nasr、Garry E. Kiefer、A. Dean Sherry
DOI:10.1021/jacs.5b09158
日期:2015.11.11
Given the known water exchange rate limitations of a previously reported Zn(II)-sensitive MRIcontrastagent, GdDOTA-diBPEN, new structural targets were rationally designed to increase the rate of water exchange to improve MRI detection sensitivity. These new sensors exhibit fine-tuned water exchange properties and, depending on the individual structure, demonstrate significantly improved longitudinal