Theoretical evidence for oxygenated intermediates in the reductive cyclization of nitrobenzenes.
Deoxygenation of nitroaromatics is a classic synthetic method for the construction of nitrogen heterocycles. The generally accepted mechanism involves exhaustive deoxygenation to a singlet nitrene. We present theoretical evidence for an alternative, 6pi-electron 5-atom electrocyclization of nitroso-styrenes, -stilbenes, and -biphenyls to nitronates. A downstream 1,5-H shift and tautomerization leads to N-hydroxy heterocycles. [reaction: see text]
Davies
Ian W
IW
Department of Process Research, Merck & Co. Inc., Rahway, NJ 07065-0900, USA. ian_davies1@merck.com
Guner
Vildan A
VA
Houk
K N
KN