Irradiation of an acetonitrile solution containing 2,3-dicyano-5,6-diphenylpyrazine with allylic silanes, benzylsilane, and ketene silyl acetal gave the mono-substituted products in excellent yields. This reaction is useful for the functionalization of pyrazine ring.
β-Carbonyl radicals as three-carbon building blocks for carbon-carbon bond forming reactions
作者:Bernd Giese、Hans Horler
DOI:10.1016/s0040-4020(01)97181-9
日期:1985.1
aldehydes, ketones and esters β-carbonyl radicals can be generated via enolization, cyclopropanation, solvomercuration and reduction with NaBH4. Radicals react with electron-poor alkenes to give products of CC-bond formingreactions (Tables 1–3). Carbonyl compounds are therefore precursors of three-carbon building blocks. The products result from reactions with “Umpolung”.
Irradiation of an acetonitrile solution containing 1,1-dicyano-2-phenylethene or 1,2,4,5-tetracyanobenzene with 2,2-dimethylcyclopropanone silylacetal in the presence of phenanthrene afforded regioselectively the addition or substitution product of C3-unit bearing ester group.