Optically active asymmetric bidentate ligands. Crystal and molecular structure of [SP-4-4-(R),(R)]-(–)<sub>589</sub>-{1-[1-(dimethylamino)ethyl]naphthyl-C<sup>2</sup>,N}[1-(diphenylphosphino)-2-(methylphenylphosphino)ethane-P,P′]-palladium(<scp>II</scp>) hexafluorophosphate
作者:Jeffrey Leitch、Geoffrey Salem、David C. R. Hockless
DOI:10.1039/dt9950000649
日期:——
isomerisation occurs in more polar solvents. Chemoselective cleavage of a phenyl group from the diphenylphosphino moiety of the free diphosphine occurred in the presence of lithium in tetrahydrofuran to give a separable 1 : 1 diastereomeric mixture of (R*,R*)- and (R*,S*)-1-(ethylphenylphosphino)-2-(methylphenylphosphino)ethane upon further reaction with bromoethane.
不对称双齿(±)-1-(二苯基膦基)-2-(甲基苯基膦基)乙烷已通过分级结晶分离了内部非对映体钯(II)配合物,该配合物含有外消旋配体和正金属化的(R)-二甲基[1-( 1-萘基)乙基]胺。配体的S对映异构体的绝对构型已通过最不溶性非对映异构钯(II)配合物(R,R)-(–)589- 1- [1-(1-(二甲基氨基)乙基]萘基-C 2,N } [1-(二苯基膦基)-2-(甲基苯基膦基)乙烷-P,P ']六氟磷酸钯(II)。X射线分析还表明,二(叔膦)的甲基苯基膦基被反式转化为拆分剂的氨基。这种反式排列保留在二氯甲烷中,但容易在分子间进行的顺式-反式异构化发生在极性更大的溶剂中。在四氢呋喃中锂的存在下,从游离二膦的二苯基膦基部分进行苯基的化学选择性切割,得到(R *,R *)-和(R *,S*)-1-(乙基苯基膦基)-2-(甲基苯基膦基)乙烷与溴乙烷进一步反应。