Optically active ligands 2 and 3 were synthesised from phenylglycine and the coordination of ligand 2 to PdCl2(CH3CN)2 and PtCl2(C6H5CN)2 was studied with 1H, 31P and 15Nâ1H-HMQC NMR spectroscopy. The results indicated P,O rather than P,N bidentate coordination. Both ligands were tested in the palladium catalysed hydrosilylation of cyclic 1,3-dienes. Asymmetric induction of up to 84% (â¤25% yield), which is the hitherto highest reported ee value for asymmetric hydrosilylation of 1,3-dienes, was achieved as measured on the allylic alcohols formed after ethanolysisâoxidation of the initially formed allylic silanes.
以苯基甘
氨酸为原料合成了光学活性
配体2和3,并用1H、31P和15N-1H-HMQC NMR谱研究了
配体2与PdCl2(CH3CN)2和PtCl2(C6H5CN)2的配位。结果表明 P,O 而不是 P,N 双齿配位。两种
配体均在
钯催化的环状 1,3-二烯氢化
硅烷化反应中进行了测试。根据对 1,3-二烯
乙醇解氧化后形成的
烯丙醇的测量,不对称诱导率高达 84%(收率 25%),这是迄今为止报道的 1,3-二烯不对称氢化
硅烷化反应的最高 ee 值。最初形成烯丙基
硅烷。