合成了手性Al III salen配合物,并使用4-苯基吡啶N-氧化物作为添加剂和三甲基甲硅烷基氰化物(TMSCN)作为氰化物来源,将其用作硝基烯烃不对称氢氰化的催化剂。如果将(2-硝基乙烯基)环己烷用作底物,在-15°C下16小时,可获得良好的β-腈(87%)和对映选择性(90%)。为了了解Al III salen络合物与添加剂的相互作用,NMR和IR光谱研究表明4-苯基吡啶N-氧化物既充当轴向配体,又有助于激活氰化物源TMSCN,从而提高了反应活性。基于光谱学研究提出了催化循环。
Organocatalytic Asymmetric Cyanosilylation of Nitroalkenes
作者:Pablo Bernal、Rosario Fernández、José M. Lassaletta
DOI:10.1002/chem.201001107
日期:——
New catalyst, new reaction: The unprecedented cyanosilylation of nitroalkenes can be efficiently catalyzed by a bifunctional quinine derivative with tetraalkylammonium cyanide and thiourea moieties. The activation of the nitroalkene by hydrogen bonding to the thiourea, together with the presence of an “active” cyanide, provides a new mode of activation that leads to products in high yields and good