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Synthesis of Cyclic N ‐Hydroxylated Ureas and Oxazolidinone Oximes Enabled by Chemoselective Iodine(III)‐Mediated Radical or Cationic Cyclizations of Unsaturated N ‐Alkoxyureas
Author(s) -
Peilleron Laure,
Retailleau Pascal,
Cariou Kevin
Publication year - 2019
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201901135
Subject(s) - hypervalent molecule , iodobenzene , chemistry , bromide , reagent , iodine , pyridinium , cationic polymerization , reactivity (psychology) , iodide , medicinal chemistry , organic chemistry , catalysis , medicine , alternative medicine , pathology
In this study we describe the reactivity of unsaturated N ‐alkoxyureas in the presence of different combinations of a hypervalent iodine(III) reagent and a bromide source or TEMPO. Three complementary cyclizations can be achieved depending on the reaction conditions. On the one hand, PIFA with pyridinium bromide leads to an oxybromination reaction. On the other hand, bis( tert ‐butylcarbonyloxy)iodobenzene with tetrabutylammonium bromide or TEMPO triggers aminobromination or aminooxyamination reactions, respectively. Control experiments showed that the three reactions proceed through distinct mechanisms: the first process is ionic while the other two follow a radical manifold.