Silylcyanation of Aldehydes, Ketones, and Imines Catalyzed by a 6,6′-Bis-sulfonamide Derivative of 7,7′-Dihydroxy-8,8′-biquinolyl (azaBINOL)
作者:Selena Milicevic Sephton、Chao Wang、Lev N. Zakharov、Paul R. Blakemore
DOI:10.1002/ejoc.201200333
日期:2012.6
structural features, bis-sulfonamide 3 and its N,N′-dimethyl derivative are exceptional in catalyzing the silylcyanation of benzaldehyde in the absence of all other additives. Hammett analysis of the competitive silylcyanation of para-substituted benzaldehydes catalyzed by 3 showed a linear free-energy relationship (R2 = 0.928) with a modest positive reaction constant (ρ = +1.52). X-ray diffraction analysis
6,6'-Bis(methylaminosulfonyl)-7,7'-dihydroxy-8,8'-biquinolyl (3) 催化 (5–10 mol-%) 三甲基氰化硅烷加成到醛(芳基、烷基和 α, β-不饱和;42–92% 产率)、酮(芳烷基、二烷基;22–82% 产率)和 N-苄基亚胺(14–78% 产率)在甲苯(0 °C 或室温)中得到脱甲硅烷基化后预期的氰醇和 Strecker 加合物。在缺乏任何一个明确结构特征的一系列密切相关的化合物中,双磺酰胺 3 及其 N,N'-二甲基衍生物在没有所有其他添加剂的情况下催化苯甲醛的甲硅烷基氰化反应方面表现出色。由 3 催化的对位取代苯甲醛的竞争性甲硅烷基氰化的哈米特分析显示线性自由能关系 (R2 = 0.928) 与适度的正反应常数 (ρ = +1.52)。(±)-3 的 X 射线衍射分析表明 C7'-OH 和 C7-O 之间存在顺式联芳构象和分子内氢键。(±)-3