作者:Wayne Vuong、Fabricio Mosquera-Guagua、Randy Sanichar、Tyler R. McDonald、Oliver P. Ernst、Lei Wang、John C. Vederas
DOI:10.1021/acs.orglett.9b04216
日期:2019.12.20
Spin-labeled aminoacids (SLAAs) are often used to determine intermolecular distances and conformations in proteins via double electron-electron resonance. Currently available SLAAs can be difficult to incorporate selectively and have little resemblance to natural side chains in proteins. Enantioselective synthesis of three spin-labeled l-amino acids is described, starting from readily available 2
Selective Reduction of Nitrones and Nitroxides to Functionalized Secondary Amines
作者:Cecília P. Sár、Tamás Kálai、Nóra M. Bárácz、Gyula Jerkovich、Kálmán Hideg
DOI:10.1080/00397919508011423
日期:1995.10
Abstract Nitrones and nitroxides were selectively reduced with Fe/AcOH to secondary amines in the presence of different functional groups (aldehyde, nitrile, carboxylic ester, activated and nonactivated double or triple bonds).
with DPROXYL-3-ylmethyl methanesulfonate (5). Fluorescence intensities (around 520nm) after reduction of the radical increased to 1.43-, 1.38-, and 1.61-folds for 2a, 2b and 3b respectively; 3a alone exhibited a decrease in intensity on reduction. Since 4 was readily solvolyzed in PBS or even methanol to afford fluorescein and 4-carboxy-TEMPO, its fluorescence change could not be measured. Hybrid compound
Synthesis and Dehydrobromination of α-Bromo Aldehyde and Ketone Nitroxyl Radical Spin Labels
作者:H. Olga Hankovszky、Kálmán Hideg、P. Cecilla Sár、M. Judit Lovas、Gyula Jerkovich
DOI:10.1055/s-1990-26788
日期:——
Various types of α-bromo aldehyde and ketone derivatives of nitroxyl radicals can be prepared in a selective bromination reaction with pyrrolidone hydrotribromide in the presence of a double bond. The saturated α-bromo aldehydes are dehydrobrominated with 1,8-diazabicyclo [5,4,0]undec-7-ene.
Facile syntheses of 3,4-disubstituted pyrroline nitroxides and their further synthetic applications
作者:Györgyi Úr、Tamás Kálai、Kálmán Hideg
DOI:10.1016/j.tetlet.2016.01.012
日期:2016.2
Lithiation of an α,β-unsaturated pyrroline nitroxide ester at the β-carbon with LTMP followed by treatment with electrophiles led to a new series of 3,4-disubstituted pyrroline nitroxides, which could be used as valuable paramagnetic building blocks. The new compounds were tested in Sonogashira and Stille cross couplingreactions, which offered methyl 1-oxyl-4-substituted-2,2,5,5-tetramethyl-2,5-d