Metal Effects on the Asymmetric Cycloaddition Reaction between 3,4-Dimethyl-1-phenylarsole and Diphenylvinylphosphine Oxide
作者:Mengtao Ma、Sumod A. Pullarkat、Mingjun Yuan、Na Zhang、Yongxin Li、Pak-Hing Leung
DOI:10.1021/om900530q
日期:2009.8.24
reaction between 3,4-dimethyl-1-phenylarsole and diphenylvinylphosphine oxide in high stereoselectivity (only one isomer). However, the neutral dichloro palladium complex obtained upon removal of the auxiliary is very unstable and instantly decomposed to produce the arsenic elimination reaction product (3,4-dimethyl-2,4-cyclohexadienyl)diphenylphosphine oxide. However when the same reaction was promoted
含原金属的有机钯配合物(S)-[1-(二甲基氨基)乙基]萘作为手性助剂已成功地用于促进3,4-二甲基-1-苯基芳醚与二苯基乙烯基氧化膦之间的不对称环加成反应(仅一种异构体)。但是,除去辅助剂后得到的中性二氯钯络合物非常不稳定,并立即分解产生砷消除反应产物(3,4-二甲基-2,4-环己二烯基)二苯基氧化膦。然而,当类似的铂络合物促进相同的反应时,仅再次获得一种立体异构体,但所得的二氯铂络合物在固态和溶液中均非常稳定,并以As-O二齿的形式配位至铂中心配体,由1确认1 H NMR和单晶X射线分析。通过用氰化钾水溶液处理配合物,可以很容易地从二氯铂配合物中释放出对映体纯的As͡P═O异双齿配体。