Molecular sieves 4A (MS4A) work effectively as base leading to catalytic generation of nickel(II) enolate or nitronate nucleophiles through deprotonation of the α-hydrogen atom of nucleophile precursors on treatment with a catalytic amount of chiral nickel(II) ions. The resulting reactive intermediates can be successfully trapped with α,β-unsaturated carbonyl electrophiles to produce the corresponding
分子筛4A(MS4A)有效地用作碱,通过催化量的手性
镍(II)离子处理,通过亲核前体的α-氢原子去质子化,催化生成烯醇
镍(II)或
亚硝酸根亲核试剂。所得的反应性中间体可以成功地被α,β-不饱和羰基亲电试剂捕集,以高收率和高对映选择性生产相应的Michael加合物。