Asymmetric Addition of Cyanide to β‐Nitroalkenes Catalysed by Chiral Salen Complexes of Titanium(IV) and Vanadium(V)
作者:Michael North、James M. Watson
DOI:10.1002/cctc.201300215
日期:2013.8
Structurally well-defined bimetallic titanium(IV) (salen) and monometallic vanadium(V) (salen) complexes have been used as catalysts for the asymmetric addition of trimethylsilyl cyanide to beta-nitroalkenes to produce chiral nitronitriles with ee values in the range of 79-89 % and conversions up to 100 % at 0 degrees C. The reaction conditions (solvent, temperature, time and vanadium complex counter-ion)
结构明确的双金属钛(IV)(salen)和单金属钒(V)(salen)配合物已用作催化剂将三甲基甲硅烷基氰化物不对称加成到β-硝基烯烃中,以生产ee值在79范围内的手性腈-89%,在0摄氏度下转化率高达100%。优化了反应条件(溶剂,温度,时间和钒络合物抗衡离子),结果表明催化剂负载量可显着降低(20至2 mol)与使用原位制备的催化剂的先前研究相比,反应温度提高了(%),反应温度提高了(-40至0摄氏度)。将结果与先前使用相同催化剂将三甲基甲硅烷基氰化物不对称加成到醛中获得的结果进行比较和对比。