Trimethylsilyl enolethers

A mixture of catalyst 110 and vinyl trimethylsilyl enolether 115 has been used in cycloisomerisation of (V-allyl-o-vinylanilines 114 and (V.A-diallyl-p-toluenesulfonamide 115 to afford the corresponding products 118 and 119, respectively (Scheme 5.30) [34]. It is believed that the active catalyst species is the ruthenium hydride NHC complex 117. 

Angular polyarenes. A soln. of startg. aldehyde and cyclohexanone trimethylsilyl enolether in methylene chloride under N2 treated dropwise at —78° with excess 1 M TiCl4 in the same solvent, after stirring at that temp, for 2 h the mixture allowed to warm to room temp., stirred for an additional 48 h, then quenched with ice-water -> 1,2,3,4-tetrahydrochrysene (Y 65%), treated with 2 eqs. 2,3-dichloro-5,6-dicyanoqui-none in refluxing benzene for 3 h chrysene (Y 77%). F.e. inch phenanthrene ring and peri-fused chrysenes s. P. Di Raddo, R.G. Harvey, Tetrahedron Letters 29, 3885-6 (1988). 

Equimolar amounts of the startg. trimethylsilyl enolether and p-bromobenzene-sulfonyl azide in anhydrous acetonitrile kept below 60° until spectroscopy shows complete reaction of the azide, then treated with water or methanol product. Y 73%. F.e. s. R.A.Wohl, Helv. 56, 1826 (1973). 

---