Frustrated Lewis Pairs from Al-E Bonds (E=Ge, Sn, Pb).

The potassium aluminyl K[Al(NON)] ([NON]=[O(SiMeNDipp)], Dipp=2,6-iPrCH) reacts with group 14 chloroamidinates E(Am)Cl (E=Ge, Sn, Pb. [Am]=[tBuC(NDipp)]) to form (NON)Al-E(Am) Lewis pairs with unsupported Al-E bonds, including the first structurally authenticated Al-Pb bond. Analysis using spectroscopic (NMR, UV-vis and Mössbauer for E=Sn), X-ray diffraction and computational (DFT, QTAIM, TD-DFT) methods conclude an Al-E σ-bond derived from a Lewis basic Al and a Lewis acidic tetrylene, with back-donation from the E s-orbital lone pair donor NBO to acceptor NBOs on Al that are derived from s/p-orbitals.

Denitrative Hydroxylation of Unactivated Nitroarenes.

A one-step method for the conversion of nitroarenes into phenols under operationally simple, transition-metal-free conditions is described. This denitrative functionalization protocol provides a concise and economical alternative to conventional three-step synthetic sequences. Experimental and computational studies suggest that nitroarenes may be substituted by an electron-catalysed radical-nucleophilic substitution (S 1) chain mechanism.