A Convenient Synthesis of 2,2?,6,6?-Tetramethoxy- 4,4?-bis(dicyclohexylphosphino)-3,3?-bipyridine (Cy-P-Phos): Application in Rh-Catalyzed Asymmetric Hydrogenation of ?-(Acylamino)acrylates
作者:Jing Wu、Terry?T.-L. Au-Yeung、Wai-Him Kwok、Jian-Xin Ji、Zhongyuan Zhou、Chi-Hung Yeung、Albert?S.?C. Chan
DOI:10.1002/adsc.200404310
日期:2005.3
The first example of the synthesis of an axially chiral bis(aryldicyclohexylphosphine) dioxide via catalytic hydrogenation of the optically resolved parent bis(aryldiphenylphosphine) dioxide was reported. The procedure for the synthesis of Cy-P-Phos (4d) has thus successfully avoided the need for an otherwise lengthy synthetic route owing to the π-excessive nature of one of the aryl groups in the latter
报道了通过光学拆分的母体双(芳基二苯基膦)二氧化物的催化加氢合成轴向手性双(芳基二环己基膦)二氧化物的第一个实例。Cy-P-Phos(4d)的合成过程因此成功地避免了对另一种冗长合成路线的需求,这是由于后者中一个芳基的π过多性质所致。与先前报道的最佳配体Xyl-P的使用相比,Cy-P-Phos在Rh(I)催化的甲基(Z)-2-乙酰氨基多辛酸甲酯衍生物的不对称加氢中产生的反应速率明显更高。 -Phos(4c),同时基本上保持对映选择性。