Copper-free asymmetric allylic alkylation with a Grignard reagent: design of the ligand and mechanistic studies.

The Cu-free asymmetric allylic alkylation, catalysed by NHC, with Grignard reagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85% ee) on large and various substrates, regardless of the nature of the Grignard reagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives with good enantiomeric excess (up to 92% ee). The methodology developed was found to be complementary with the Cu-catalysed version. Several new NHCs were tested with improved efficiency. In addition, mechanistic studies, using NMR spectroscopy, led to the discovery of the catalytically active species.

Novel thermal and microwave-assisted facile route to naphthalen-2(1H)-ones via an oxidative alkoxylation-ring-opening protocol.

Several novel 1,1-disubstituted-8-hydroxynaphthalen-2(1H)-ones have been efficiently synthesized via a two-step sequence from 2-hydroxy-1-naphthaldehyde oxime. The methodology involves oxidative ring closure and alkoxylation to 3a-alkoxynaphtho[1,8-de][1,2]oxazin-4(3aH)-ones, followed by thermal ring-opening. Both thermal and microwave irradiation conditions were used. A novel one-pot reaction of oxime to 8-isopropoxynaphthalene-1,7-diol using microwave irradiation is also reported.