29577-51-3Relevant academic research and scientific papers
Novel approach towards the synthesis of 3,3a,4,5-tetrahydroquinolino[4,3-c] isoxazole derivatives: Application to the preparation of previously unattainable 3a,4-dihydroazabenzopyrano[4,3-c]isoxazole scaffolds
Alcázar, Jesús,Alonso, José Manuel,Andrés, José Ignacio,Bartolomé, José Manuel,Fernández, Javier
, p. 3139 - 3141 (2005)
A novel synthetic approach towards the preparation of 3-substituted-7,8- dimethoxy-3,3a,4,5-tetrahydroquinolino[4,3-c]isoxazole derivatives is reported. Further application of this methodology to the preparation of previously unattainable 3a,4-dihydroazab
Photolysis of ortho-nitrobenzylic derivatives: The importance of the leaving group
Solomek, Tomas,Mercier, Sebastien,Bally, Thomas,Bochet, Christian G.
experimental part, p. 548 - 555 (2012/06/30)
Quantum yields for the photoinduced release of seven different commonly used leaving groups (LGs) from the o-nitroveratryl protecting group were measured. It was found that these quantum yields depend strongly on the nature of the LGs. We show that the quantum efficiency with which the LGs are released correlates with the stabilization that these LGs provide to o-nitrobenzyl-type radicals because radical stabilizing groups weaken the C-H bond that is cleaved in the photoinduced hydrogen atom transfer step, and hence lower the barrier for this process. At the same time these substituents lower the endothermicity of the thermal hydrogen atom transfer and thus increase the barrier for the reverse process, thereby enhancing the part of the initially formed aci-nitro intermediates which undergo cyclization (which ultimately leads to LG release). Radical stabilization energies computed by DFT methods are thus a useful predictor of the relative efficiency with which LGs are photoreleased from o-nitrobenzyl protecting groups.
Design, synthesis and antibacterial activity of novel N-formylhydroxylamine derivatives as PDF inhibitors
Yin,Jia,Zhao,Xu,Tang,Wang
experimental part, p. 695 - 703 (2011/07/29)
A new series of N-formylhydroxylamines 11a-i have been synthesized through a multi-step protocol starting from diethyl malonate. These compounds have been structurally characterized by IR, 1H NMR and HRMS. All the synthesized compounds 11a-i have been screened for antibacterial activities. All the compounds are found to exhibit potent in vitro inhibitory activity against Staphylococcus aureus and relatively weak antibacterial activity against Klebsiella pneumoniae.
Enzymatic synthesis of caged NADP cofactors: Aqueous NADP photorelease and optical properties
Salerno,Magde,Patron
, p. 3971 - 3981 (2007/10/03)
The synthesis of caged NADP analogues 18, 19, and 20 has been accomplished by utilizing the transglycosidase activity of solubilized NAD glycohydrolase (porcine brain) to incorporate caged nicotinamides 2, 3, and 4 into NADP. The synthesis of several nicotinamides modified at the carboxamide with o-nitrobenzyl photolabile groups is demonstrated as well as their potential for enzymatic transglycosidation. These results further demonstrate the feasibility of direct enzymatic transglycosidation of sterically hindered substrates into NAD(P), although high nicotinamide analogue water solubility was found to be a necessary trait for yield enhancement with certain analogues. Caged analogues were surveyed under aqueous conditions for net NADP photorelease, while the UV and fluorescent properties of both analogues and their photobyproducts were assessed for compatibility with systems that rely on optical monitoring of enzyme activity. A highly water-soluble α-methyl-o-nitrobenzyl group 8 was developed for the synthesis of 20 in order to enhance net NADP photorelease. Compound 20 demonstrated a high 75% net NADP photoreleased without substantial UV optical blackening or fluorescent byproducts. Analogues 18 and 19 were shown by ESI/MALDI-MS to photogenerate primarily adducts of NADP with deleterious UV and fluorescent properties. Our work stresses the superior release properties conferred by α-methyl substitution on aqueous carboxamide photorelease from o-nitrobenzyl compounds.
