Ethynyltriisopropoxytitanium reactions with pyrimidinones
作者:Frode Rise、David Grace、Kjell Undheim
DOI:10.1016/0022-328x(88)80007-x
日期:1988.1
pyrimidin-2(1H)-ones with exclusive carbon-carbon bond formation at C(6). The products after quenching ethynylmagnesium bromide with chlorotriisopropoxytitanium at −10°C are the mesityl oxide adducts with the pyrimidinones with the new carbon-carbon bond at C(6). Mesityl oxide, as its lithium enolate at −80°C, forms a mixture of the 3,4- and the 3,6-dihydro-isomeric adducts. High resolution NMR was used for the structure
Aryl- and alkynyltri-isopropoxytitanium reagents in regioselective carbon-carbon bond formation in azines
作者:Lise-Lotte Gundersen、Frode Rise、Kjell Undheim
DOI:10.1016/0040-4020(92)80015-8
日期:1992.7
results from 1:1-adduct formation between an aryltriisopropoxytitanium reagent and N-isobutyloxycarbonyl- or an N-silyloxymethyl-3-cyanopyridinium salt after successive DDQ dehydrogenation and cleavage of the 1-substituent. Complete regioselectivity for new CC bondformation in the 4-position results in the adduct formation between aryl- and phenylethynyltri-isopropoxytitanium reagents and pyrimidin-2(1H)-ones;
Regioselectivity in reactions of alkynylmetal complexes with pyrimidinones
作者:Frode Rise、Kjell Undheim
DOI:10.1016/0022-328x(85)80160-1
日期:1985.8
Regioselectivity is observed in 11-adduct formation between phenylethynyltriisopropoxytitanium and 2(1/H)-pyrimidinones; the new carbon-carbon bond is formed at C(4). In contrast the 3,4- and 3,6-dihydro products are formed together from the corresponding magnesium and lithium reagents, but from the magnesium compound the major product is the 3,6-dihydro isomer. Ethynylmagnesium bromide gives equimolar