The optically pure monophosphites P(OAr)(BINOLate) (7, where Ar = 2,4-di-tert-butylphenyl) have been prepared by treatment of PCl2(OAr) with R- or S-BINOL. Treatment of [PdCl2(NCMe)2] with 7 gave [PdCl2(7)2] (9) or the binuclear orthometallated complex [Pd2Cl2(7-H)2] (8) depending on the reaction conditions. Bridge cleavage reactions of 8 gave [PdCl(7-H)(L)] with L trans to carbon when L = PPh3 or 7 and cis to carbon when L = N-heterocyclic carbene. Treatment of [PtCl2(NCtBu)2] with 7 gave [PtCl2(7)2] (18) which upon further reaction with PtCl2 furnished a mixture of binuclear [Pt2Cl2(7-H)2] (17) and cis-[PtCl(7-H)(7)] (19). The palladium complexes containing cyclometallated 7 were screened for catalysis of 1,4-conjugate addition of phenylboronic acid to cyclohexen-2-one and the allylation of benzaldehyde with allyltributyltin. Conversions were generally high in each case but enantioselectivities were low (15% e.e. at best). The X-ray crystal structures of 8, 17 and [PdCl(7-H)(NHC)] (10a, where NHC = 1,3-(dimesityl)imidazolidin-2-ylidene) have been determined.
通过将PCl2(OAr)与R-或S-BINOL反应,制备了光学纯的单
膦酸酯P(OAr)(BINOLate) (7, 其中Ar = 2,4-二
叔丁基苯基)。将[PdCl2(NCMe)2]与7反应,根据反应条件得到[PdCl2(7)2] (9)或二核邻
金属配合物[Pd2Cl2(7-H)2] (8)。8的桥断裂反应得到当L = PPh3或7时与碳反式排列的[PdCl(7-H)(L)],当L = N-杂环卡宾时与碳顺式排列。将[PtCl2(NCtBu)2]与7反应得到[PtCl2(7)2] (18),进一步与PtCl2反应得到二核[Pt2Cl2(7-H)2] (17)和顺式-[PtCl(7-H)(7)] (19)的混合物。含环
金属化7的
钯配合物被筛选用于催化苯
硼酸对
环己烯-2-酮的1,4-共轭加成和
苯甲醛与三
丁基锡烯烃的烯丙基化反应。每种情况下的转化率一般都很高,但对映选择性较低(最好的情况下为15% 对映体过量)。8、17和[PdCl(7-H)(NHC)] (10a, 其中NHC = 1,3-(二甲基)
咪唑啉-2-亚基)的X射线晶体结构已经确定。