Synthesis of Trifluoromethyl-Substituted Arenes, Cyclohexenones and Pyran-4-ones by Cyclocondensation of 1,3-Bis(silyloxy)-1,3-butadienes with 4,4-Dimethoxy-1,1,1-trifluorobut-3-en-2-one: Influence of the Lewis Acid on the Product Distribution
作者:Alina Bunescu、Sebastian Reimann、Mathias Lubbe、Anke Spannenberg、Peter Langer
DOI:10.1021/jo900702u
日期:2009.7.17
TiCl4-mediated formal [3 + 3] cyclocondensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 4,4-dimethoxy-1,1,1-trifluorobut-3-en-2-one afforded a variety of functionalized 4-methoxy-6-(trifluoromethyl)salicylates and 3-methoxy-5-(trifluoromethyl)phenols with very good regioselectivity. The Me3SiOTf-mediated cyclization of 1,3-bis(trimethylsilyloxy)-1,3-butadienes, containing no substituent located
提供TiCl 4介导的1,3-双(三甲基甲硅烷氧基)-1,3-丁二烯与4,4-二甲氧基-1,1,1-三氟丁-3-烯-2-酮的缩合[3 + 3]环缩合反应具有非常好的区域选择性的各种官能化的4-甲氧基-6-(三氟甲基)水杨酸酯和3-甲氧基-5-(三氟甲基)苯酚。Me 3 SiOTf介导的1,3-双(三甲基甲硅烷氧基)-1,3-丁二烯的环化反应,该取代基不包含位于二烯碳原子C-4处的取代基(R 1 = H),导致形成三氟甲基-取代的吡喃-4-酮。相反,当使用二烯时确实形成了三氟甲基化的环己烯酮,所述二烯确实含有位于碳C-4(R 1 ≠H)上的取代基。