A variety of functionalized benzonitriles were regioselectively prepared by formal [3+3] cyclocondensation of 1,3-bis(silyloxy)-1,3-butadienes with 3-ethoxy- and 3-silyloxy-2-cyano-2-en-1-ones. arenes - benzonitriles - cyclizations - regioselectivity - silylenolethers
Regioselective Synthesis of 6-[Chloro(difluoro)methyl]salicylates by [3+3] Cyclocondensations of 1,3-Bis(trimethylsilyloxy)buta-1,3-dienes with 1-Chloro-1,1-difluoro-4-(trimethylsilyloxy)pent-3-en-2-one
作者:Silke Erfle、Sebastian Reimann、Alina Bunescu、Zharylkasyn A. Abilov、Anke Spannenberg、Peter Langer
DOI:10.1002/hlca.201100494
日期:2012.6
cyclocondensation of various 1,3‐bis(trimethylsilyloxy)buta‐1,3‐dienes with 1‐chloro‐1,1‐difluoro‐4‐(trimethylsilyloxy)pent‐3‐en‐2‐one provides a regioselective access to novel 6‐(chlorodifluoromethyl)salicylates (=6‐(chlorodifluoromethyl)‐2‐hydroxybenzoates) with very good regioselectivity. For selected products, it was demonstrated that the CF2Cl group can be transformed to CF2H and CF2(Allyl) by free‐radical
Regioselective Synthesis of Trichloromethyl-Substituted Salicylates and Cyclohexenones by One-Pot Cyclizations of 1,3-Bis(trimethylsilyloxy)buta-1,3-dienes
作者:Sebastian Reimann、Alina Bunescu、Andranik Petrosyan、Muhammad Sharif、Silke Erfle、Constantin Mamat、Tariel V. Ghochikyan、Ashot S. Saghyan、Anke Spannenberg、Alexander Villinger、Peter Langer
DOI:10.1002/hlca.201200595
日期:2013.10
6‐(trichloromethyl)salicylates (=2‐hydroxy‐6‐(trichloromethyl)benzoates) were prepared by TiCl4‐mediated cyclization of 1,3‐bis(trimethylsilyloxy)buta‐1,3‐dienes with 1,1,1‐trichloro‐4,4‐dimethoxybut‐3‐en‐2‐one. The employment of trimethylsilyl trifluoromethanesulfonate (Me3SiOTf) as Lewis acid resulted in the formation of trichloromethyl‐substituted cyclohexenones. The cyclizations proceeded with good‐to‐very‐good
Regioselective synthesis of 5-ethoxycarbonyl-, 5-acetyl- and 5-trifluoroacetyl-6-trifluoromethylsalicylates by one-pot cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-alkoxy-2-alken-1-ones
作者:Simone Ladzik、Mathias Lubbe、Nazken K. Kelzhanova、Zharylkasyn A. Abilov、Holger Feist、Peter Langer
DOI:10.1016/j.jfluchem.2012.02.002
日期:2012.4
5-trifluoroacetyl-, and 5-acetyl-6-trifluoromethylsalicylates were prepared by one-potcyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-alkoxy-2-alken-1-ones. The reactions proceeded with very good regioselectivity by conjugate addition of the terminal carbon atom of the diene to the enone and subsequent cyclization. The cyclization proceeded in most cases via the trifluoroacetyl group.