Investigation of the hydrogen bond donating ability of 1,8-naphthalenediol by NMR spectroscopy and its use as a hydrogen bonding catalyst

Abstract

The hydrogen bond donating ability of 1,8-naphthalenediol was investigated via a series of ${}^1H$, ${}^{13}C$, and ${}^{31}P$NMR experiments. Complexation studies using triphenylphosphine oxide and cyclohexanone as hydrogen bond acceptorsrevealed that 1,8-naphthalenediol is a more effective hydrogen bond donor compared to 1-naphthol and 8-methoxy-1-naphthol. Afterwards, its effectiveness as a hydrogen bonding catalyst was demonstrated in the Friedel–Crafts-typeaddition reaction of indole to trans-β -nitrostyrene.