TY - JOUR
T1 - Effective 2,6-substitution of piperidine nitroxyl radical by carbonyl compound
AU - Sakai, Kiyoshi
AU - Yamada, Ken ichi
AU - Yamasaki, Toshihide
AU - Kinoshita, Yuichi
AU - Mito, Fumiya
AU - Utsumi, Hideo
N1 - Funding Information:
We thank Dr. Ryoichi Ando for X-ray crystallographic analysis. This study was partially supported by the Development of Systems and Technology for Advanced Measurement and Analysis of the Japan Science and Technology Agency and a Grant-in-Aid for Young Scientists from the Japan Society for the Promotion of Science.
PY - 2010/3/27
Y1 - 2010/3/27
N2 - Nitroxyl radicals (nitroxides) with unpaired electron are widely used as antioxidants, contrast agents, and spin probes. Although piperidine nitroxyl radicals have many applications, these are mainly tetramethylpiperidine compounds, and only a few reports consider the substitution of N-O surround as a reaction site, such as 2,2,6,6-tetrasubstituted piperidine nitroxyl radicals. Our results revealed that the 2,6-position of the 2,2,6,6-tetramethylpiperidin-4-one compound was substituted by cyclohexyl groups to produce 2,2,6,6-tetrasubstituted piperidin-4-one derivatives under mild reaction conditions. An interesting result was obtained by using 15N-labeled NH4Cl instead of 14NH4Cl: it gave 15N-labeled 2,2,6,6-tetrasubstituted piperidin-4-one-1-oxyls with a high 15N content. In conclusion, the new method for the synthesis of nitroxyl radicals readily yields 2,2,6,6-tetrasubstituted piperidin-4-one under mild conditions.
AB - Nitroxyl radicals (nitroxides) with unpaired electron are widely used as antioxidants, contrast agents, and spin probes. Although piperidine nitroxyl radicals have many applications, these are mainly tetramethylpiperidine compounds, and only a few reports consider the substitution of N-O surround as a reaction site, such as 2,2,6,6-tetrasubstituted piperidine nitroxyl radicals. Our results revealed that the 2,6-position of the 2,2,6,6-tetramethylpiperidin-4-one compound was substituted by cyclohexyl groups to produce 2,2,6,6-tetrasubstituted piperidin-4-one derivatives under mild reaction conditions. An interesting result was obtained by using 15N-labeled NH4Cl instead of 14NH4Cl: it gave 15N-labeled 2,2,6,6-tetrasubstituted piperidin-4-one-1-oxyls with a high 15N content. In conclusion, the new method for the synthesis of nitroxyl radicals readily yields 2,2,6,6-tetrasubstituted piperidin-4-one under mild conditions.
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U2 - 10.1016/j.tet.2010.02.004
DO - 10.1016/j.tet.2010.02.004
M3 - Article
AN - SCOPUS:77349083006
VL - 66
SP - 2311
EP - 2315
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 13
ER -