-1,3-Ph 2 -C 3 H 3 )P] (6a, 6d) were obtained. Palladium allyl complexes were screened as precatalysts in the allylicsubstitution of rac-3-acetoxy-1,3-diphenyl-1-propene (I) and (E)-3-acetoxy-1-phenyl-1-propene (III) with dimethyl malonate as the nucleophile. The various catalytic precursors showed a wide range of activity and selectivity. The bismonodentate phosphane complexes 3 are more active than
selenoxides having an opticallyactive binaphthyl skeleton work as the reagents for enantioselective oxidation of phosphines to the correspondingphosphineoxides. Treatment of a racemic 2-oxazolin-2-ylferrocenylphosphine with one of the selenoxides in carbon tetrachloride in the presence of phenol affords the correspondingphosphineoxide together with the unreacted starting phosphine, both with moderate
具有旋光联萘骨架的环状硒氧化物用作将膦对映选择性氧化成相应氧化膦的试剂。在苯酚的存在下,用四氯化碳中的一种氧化硒处理外消旋 2-恶唑啉-2-基二茂铁基膦,得到相应的氧化膦和未反应的起始膦,两者都具有中等对映选择性(氧化膦,高达 13% ee ; 膦,高达 29% ee)。
Neutral p-cymene ruthenium complexes with P-stereogenic monophosphines. New catalytic precursors in enantioselective transfer hydrogenation and cyclopropanation
1-phenylethanol. Cationic complexes formed upon treatment of C with one equivalent of AgSbF6 or (Et3O)PF6 are active in the cyclopropanation reaction of styrene and α-methylstyrene by ethyl diazoacetate. Low to moderate conversions (up to 58%), diastereoselectivities (up to 40% de), and moderate enantioselectivities (up to 69% ee) have been found. For both reactions, bulky complexes and C6 in particular
一家八中性,pseudotetrahedral钢琴凳钌络合物Ç,所述类型的合成将[RuCl 2(p -cymene)(PArPhR)](Ar为1-萘基,9-菲基和2-联苯基; R = Me中,我-已制备并表征了Pr,OMe,-CH 2 SiMe 3和-CH 2 SiPh 3,包括C6的X射线晶体结构(Ar = 2-联苯基; R = i -Pr)。这些配合物在叔丁氧基钾存在下催化2-苯丙醇在回流的2-丙醇中催化苯乙酮的不对称氢转移反应,在达到S的24小时后达到完全转化和高达45%ee1-苯基乙醇的对映体。用一当量的AgSbF 6或(Et 3 O)PF 6处理C时形成的阳离子络合物在苯乙烯和α-甲基苯乙烯通过重氮乙酸乙酯的环丙烷化反应中具有活性。已发现低至中等的转化率(高达58%),非对映选择性(高达40%de)和中等对映选择性(高达69%ee)。对于这两种反应,特别是笨重的配合物和C6均能达到最佳效果。
Allylpalladium Complexes with <i>P</i>-Stereogenic Monodentate Phosphines. Application in the Asymmetric Hydrovinylation of Styrene
作者:Arnald Grabulosa、Guillermo Muller、Juan I. Ordinas、Antonio Mezzetti、Miguel Ángel Maestro、Mercè Font-Bardia、Xavier Solans
DOI:10.1021/om050421v
日期:2005.10.1
complexes [PdCl(ally)P*]. The reaction carried out with deuterated styrene shows the clean C−H addition to the vinyl double bond of stryrene and confirms the irreversible nature of the insertion of styrene in the palladium hydride intermediate. The hydrovinylation reaction using substituted styrene with a potentially secondary coordination atom occurs only when the substitution is in the phenyl ring and
一组P-立体异构单齿膦S -PPhRR'(R = 1-萘基,9-菲基或邻-联苯基,R'= CH 3-,i -C 3 H 8-和Ph 3 SiCH 2-)通过在由(-)-麻黄碱和双(N,N-二乙氨基)苯基膦获得的恶杂磷硼烷硼烷上进行连续取代反应,制备了α-己内酰胺。与双核烯丙基化合物[Pd(μ-Cl)(烯丙基)] 2的反应产生中性[PdCl(烯丙基)P *]配合物。当烯丙基= 2-CH 3 -C 3 H 4(5),由于钯原子周围的R-或S-几何形状,溶液中出现了两种异构体。膦的鉴别作用很小,并且对PPh(o -Ph 2)(CH 2 SiPh 3)观察到最大异构体比率。通过X射线衍射确定的两个配合物的分子结构具有P * = PPh(o -Ph 2)(i -Pr)和PPh(o -Ph 2)(OMe),表明烯丙基部分的非对称配位非常相似。磷原子的反式影响更大。当烯丙基= 1-C 6 H 5时-C 3
CHODKIEWICZ W.; JORE D.; WODZKI W., TETRAHEDRON LETT., 1979, NO 12, 1069-1072