To obtain further insight into the new ruthenium-catalyzed reaction of carbon–hydrogenbonds in aromatic ketones with olefins, the effect of various substituents at the aromatic ring is examined. Reaction of o-methylacetophenone with triethoxyvinylsilane (2) in the presence of [Ru(H)2(CO)(PPh3)3] (3)as the catalyst gave the 1 : 1 addition product in quantitative yield. Similarly, the ketone having
Effective conditions for the hydroarylation of vinylsilanes, allowing functionalization of various aromatic ketones in good yields at low temperature, using isopropanol, a protic solvent, are reported. Moreover, conducting this C−C bond-forming reaction under conditions similar to those used for hydride transfer reduction, the reduction of the ketone could be suppressed, simply by using acetone cosolvent
Ruthenium-catalysed ortho alkylation of hydroxyacetophenones; the functionalisation of ring C aromatic diterpenoids
作者:Paul W.R. Harris、Paul D. Woodgate
DOI:10.1016/s0022-328x(96)06697-1
日期:1997.3
Ortho C-H bond coupling of some 2-alkoxyacetophenones with olefins catalysed by ruthenium complexes results in a high yield of the ortho alkylated product, providing that a suitable protecting group is employed. No such protection was required for a para-alkoxy group; an activating effect was also observed. Bicyclic and tricyclic analogues react similarly.