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 bond formation in the 4-position results in the adduct formation between aryl- and phenylethynyltri-isopropoxytitanium reagents and pyrimidin-2(1H)-ones;
吡啶的4位区域选择性芳基化是由DDQ连续脱氢和1位取代基裂解后,芳基三异丙氧基钛试剂与N-异丁氧基羰基-或N-甲硅烷氧基甲基-3-氰基吡啶鎓盐之间的1:1加合物形成而引起的。在4位上形成新的C bondC键的完全区域选择性导致芳基和苯基乙炔基三异丙氧基钛试剂与嘧啶2(1 H)-酮之间形成加合物。乙炔基三异丙氧基钛与新的CC键形成在6位上。