Two novel cyclic aromatic analogues of the Hendrickson POP reagent, 1,1,3,3-tetraphenyl-1,3-dihydro-2,1,3-benzoxadiphosphole-1,3-diium bis(trifluoromethanesulfinate) and bis(trifluoromethanesulfonate), have been readily prepared by the treatment of 1,2-bis(diphenylphosphino)benzene or 1,2-bis(diphenylphosphoryl)benzene, respectively, with trifluoromethanesulfonic anhydride in dichloromethane. 31P and 19F NMR studies indicated that while the latter complex is formed as the sole product, the former species was shown to be the predominant component in equilibrium with 1-(diphenylphosphino)-2-[diphenyl(trifluoromethylsulfonyloxy)phosphonio]benzene trifluoromethanesulfinate and 1,2-bis[diphenyl(trifluoromethylsulfonyloxy) phosphonio]benzene bis(trifluoromethanesulfinate). The dehydrating POP systems were exploited in the conversion of aldoximes into nitriles. The dehydration occurred rapidly at room temperature and produced high yields with a variety of alkyl- and arylaldoximes, tolerating a wide range of substrates and functional groups.
- Hendrickson reagent
- trifluoromethanesulfonic anhydride
ASJC Scopus subject areas
- Organic Chemistry