Martinez Gloria, Arumugam Jayanthi, Jacobs Hollie K, Gopalan Aravamudan S
Department of Chemistry and Biochemistry, MSC 3C, New Mexico State University, Las Cruces, NM 88003-8001 USA.
Tetrahedron Lett. 2013 Feb 13;54(7):630-634. doi: 10.1016/j.tetlet.2012.11.136.
The HOPO vinyl sulfonamide 3 and the corresponding HOPO acrylamide 10, were easily prepared by short synthetic sequences. Investigation of the aza-Michael reactions of these linkers showed that they proceed at a higher rate in solvent systems containing water. The scope and limits of the aza-Michael reactions of 3 and 10 were examined. Reagents 3 and 10 reacted cleanly with piperazine to give the corresponding adducts which were deprotected to give the di-HOPO ligands 7 and 16. Reaction of HOPO acrylamide 10 with 1,4,7-triazacyclononane gave the tris-adduct 17 which was deprotected to give the desired tris-HOPO ligand 18. Overall, the aza-Michael reactions of 3 and 10 appear to be governed not only by the solvent but also by the nature of the amine and the solubility of the reaction intermediates.
HOPO乙烯基磺酰胺3和相应的HOPO丙烯酰胺10可通过简短的合成序列轻松制备。对这些连接体的氮杂迈克尔反应的研究表明，它们在含水的溶剂体系中反应速率更高。研究了3和10的氮杂迈克尔反应的范围和局限性。试剂3和10与哌嗪顺利反应，得到相应的加合物，脱保护后得到二-HOPO配体7和16。HOPO丙烯酰胺10与1,4,7-三氮杂环壬烷反应得到三加合物17，脱保护后得到所需的三-HOPO配体18。总体而言，3和10的氮杂迈克尔反应似乎不仅受溶剂影响，还受胺的性质和反应中间体的溶解度影响。
