Orthogonal aerobic conversion of N-benzyl amidoximes to 1,2,4-oxadiazoles or quinazolinones.
Concise synthesis of 1,2,4-oxadiazoles was achieved by heating N-benzyl amidoximes with K3PO4 in DMF at 60 °C under an O2 atmosphere via benzylic C-H oxygenation. On the other hand, aerobic treatment of N-benzyl amidoximes with Cs2CO3 in DMSO at 100 °C could result in oxidative skeletal rearrangement to deliver quinazolinones as a major product. This orthogonal product selectivity could be realized by difference of the reaction temperature as well as selection of the solvents and inorganic bases.
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Feng-Lian
FL
Zhang
Yi-Feng
YF
Wang
Shunsuke
S
Chiba
D000578:Amidines / Q000737:chemistry*; D015394:Molecular Structure; D010069:Oxadiazoles / Q000138:chemical synthesis* / Q000737:chemistry; D010091:Oximes / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D052999:Quinazolinones / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature
D000578:Amidines; D010069:Oxadiazoles; D010091:Oximes; D052999:Quinazolinones; D010100:Oxygen