Synthesis and application of new iminopyridine ligands in the enantioselective palladium-catalyzed allylic alkylation
作者:Maurizio Solinas、Barbara Sechi、Giorgio Chelucci、Salvatore Baldino、José R. Pedro、Gonzalo Blay
DOI:10.1016/j.molcata.2014.01.006
日期:2014.4
A variety of iminopyridines were obtained by condensation of chiral amines with pyridine-2-carboxaldehyde and quinoline-8-carbaldehyde, or of aminoalkylpyridine derivatives with chiral ketones. These ligands were assessed in the enantioselective palladium catalyzed allylic substitution of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate affording the product dimethyl 1,3-diphenylprop-2-enylmalonate
通过手性胺与吡啶-2-羧醛和喹啉-8-甲醛的缩合,或氨基烷基吡啶衍生物与手性酮的缩合,可获得各种亚氨基吡啶。这些配体在丙二酸二甲酯的对映选择性钯催化的1,3-二苯丙-2-烯丙基乙酸酯的对映选择性钯催化的烯丙基取代中得到了评估,从而以良好的收率和中等的对映选择性(高达62%ee)提供了1,3-二苯丙-2-烯丙二酸二甲酯。 )。发现催化活性和对映选择性高度依赖于配体的空间性质。通过基于樟脑骨架的亚氨基吡啶可获得最佳的对映选择性(62%ee)。