A study of chiral oxazoline ligands with a 1,2,4-triazine and other six-membered aza-heteroaromatic rings and their application in Cu-catalysed asymmetric nitroaldol reactions

作者：Wolinska Ewa^*

来源：Tetrahedron: Asymmetry , 2014, 25(22): 1478-1487.

DOI：10.1016/j.tetasy.2014.10.001

Enantiomerically pure oxazoline ligands with variously substituted 1,2,4-triazine rings have been synthesized using the Pd-catalysed cross-coupling amination of 3-halo-1,2,4-triazines. The catalytic efficiency of the ligands was studied in the asymmetric Henry reaction of nitromethane with several aldehydes. The appropriate beta-nitro alcohols were formed in good yields (up to 93%) and with up to 78% ee. The impact of the substitution of the 1,2,4-triazine ring on the nitroaldol reaction is discussed. In order to investigate the influence of the 1,2,4-triazine ring on the catalytic activity of the ligands, ligands where the 1,2,4-triazine ring was replaced by a pyridine, pyrimidine, pyrazine or pyridine N-oxide ring were synthesized and applied to asymmetric nitroaldol reactions.

• 出版日期2014-11-30