Catalytic Deallylation of Allyl- and Diallylmalonates
摘要:
Substituted allylmalonates undergo the selective C-C bond cleavage in the presence of triethylaluminum and a catalytic amount of nickel and ruthenium phosphine complexes, resulting in the loss of the allyl moiety and formation of monosubstituted malonates. Comparison of reactivity of the nickel and ruthenium complexes showed that the use of the former is general with respect to the structure of the substituted allylmalonates, and the activity of the latter depended on the substitution pattern of the double bond of the allylic moiety. The smooth deallylation may encourage the use of the allyl group as a protective group for the acidic hydrogen in malonates.
New chiral phosphoramidites with an amide moiety were used for iridium-catalyzed asymmetric allylicalkylation reactions. The best results were obtained with a ligand bearing an oxazolidinone moiety. The reaction of cinnamyl acetate with diethyl sodiomalonate without the use of lithium chloride gave the branched product with 94% ee.
Schiff bases containing ferrocenyl and thienyl units and their utility in the palladium catalyzed allylic alkylation of cinnamyl acetate
作者:David Pou、Ana E. Platero-Prats、Sonia Pérez、Concepción López、Xavier Solans、Mercè Font-Bardía、Piet W.N.M. van Leeuwen、Gino P.F. van Strijdonck、Zoraida Freixa
DOI:10.1016/j.jorganchem.2007.07.027
日期:2007.10
The synthesis and characterization of two new ferrocenyl Schiff bases: [Fc-CHN–(CH2)n–(C4H3S)] (2) Fc represents (η5-C5H5)Fe(η5-C5H4)– and n = 1(2a) or 2(2b)} containing the thienyl (C4H3S) group are reported. NMR studies indicate that 2 have the anti-(E) conformation in solution and the X-ray crystal structure of 2a confirms that it also adopts the anti-(E) form in the solid state. Ligands 2 have
的合成和两个新的二茂铁席夫碱表征:[Fc的CHN-(CH 2)ñ - (C 4 H ^ 3 S)(2)的Fc表示(η 5 -C 5 H ^ 5)的Fe(η 5 -据报道含有噻吩基(C 4 H 3 S)基团的C 5 H 4)-和n = 1(2a)或2(2b)} 。NMR研究表明2在溶液中具有抗-(E)构象,并且2a的X射线晶体结构确认它也采用固态的抗-(E)形式。使用2-甲基丙二酸二乙酯钠作为亲核试剂,在钯催化的乙酸(E)-3-苯基-2-丙烯-1-基(肉桂基)的烯丙基烷基化反应中对配体2进行了测试。的反应2与[加入Pd(η 3 -1-PH-C 3 H ^ 4)(μ-Cl)的] 2稍微过量K的存在[PF 6 ]制备[将Pd(η 3 -1-PH- C 3 H 4)Fc-CHN–(CH 2)n-(C 4 H 3S)}] [PF 6 ] n = 1(5a)或2(5b)},它们是该催化过程
Direct Allylation of Active Methylene Compounds with Allylic Alcohols by Use of Palladium/Phosphine-Borane Catalyst System
The C−C bond formation between active methylene compounds and allylic alcohols has been newly developed by using a palladium complex as a catalyst together with a phosphine‐borane ligand. The best phosphine‐borane ligand for this direct allylation has been revealed to be Ph2P(CH2)4(9‐BBN) to produce a variety of desirable allylated products in high yields.
作者:Ana E. Platero-Prats、Sonia Pérez、Concepción López、Xavier Solans、Mercè Font-Bardía、Piet W.N.M. van Leeuwen、Gino P.F. van Strijdonck、Zoraida Freixa
DOI:10.1016/j.jorganchem.2007.06.016
日期:2007.9
(1a) with palladium(II)–allyl complexes [Pd(η3-1R1,3R2-C3H3)(μ-Cl)]2 R1 = H and R2 = H (2), Ph (3) or R1 = R2 = Ph (4)} is reported. Treatment of 1a with 2 or 3 in a molar ratio Pd(II):1a = 1} in CH2Cl2 at 298 K produced [Pd(η3-3R2-C3H4)FcCHN–CH(Me)(Ph)}Cl] R2 = H (5a) or Ph (6a)}. When the reaction was carried out under identical experimental conditions usingcomplex 4 as starting material no evidence
对映体纯ferrocenylimine(的反应性的研究小号Ç) - [FcCHN-CH(Me)中(PH)] FC =(η 5 -C 5 H ^ 5)的Fe (η 5 -C 5 H ^ 4) - }(图1A)与钯(II) -烯丙基配合物[将Pd(η 3 -1R 1,3R 2 -C 3 H ^ 3)(μ-Cl)的] 2 R 1 = H和R 2 = H(2)中,Ph(3)或R 1 = R 2 = Ph(4)}。治疗1a用2或3 的摩尔比Pd(II):1A = 1}在CH 2氯2在298K产生的[将Pd(η 3 -3R 2 -C 3 H ^ 4)FcCHN-CH(Me)中(PH )} Cl] R 2 = H(5a)或Ph(6a)}。当反应使用复杂的相同的实验条件下进行4作为起始原料,没有证据为[钯形成(η 3 -1,3-PH 2 -C 3 H ^ 3)FcCHN-CH(Me)中(PH)
Bulky Monodentate Phosphoramidites in Palladium-Catalyzed Allylic Alkylation Reactions: Aspects of Regioselectivity and Enantioselectivity
作者:Maarten D. K. Boele、Paul C. J. Kamer、Martin Lutz、Anthony L. Spek、Johannes G. de Vries、Piet W. N. M. van Leeuwen、Gino P. F. van Strijdonck
DOI:10.1002/chem.200400154
日期:2004.12.17
A series of bulky monodentatephosphoramidite ligands, based on biphenol, BINOL and TADDOL backbones, have been employed in the Pd-catalysed allylic alkylation reaction. Reaction of disodium diethyl 2-methyl malonate with monosubstituted allylic substrates in the presence of palladium complexes of the phosphoramidite ligands proceeds smoothly at room temperature. The regioselectivities observed depend
基于双酚,BINOL和TADDOL主链的一系列庞大的单齿亚磷酰胺配体已用于Pd催化的烯丙基烷基化反应中。在亚磷酰胺配体的钯配合物存在下,2-甲基丙二酸二乙酯二钠与单取代的烯丙基底物的反应在室温下顺利进行。观察到的区域选择性在很大程度上取决于离去基团和烯丙基起始化合物的几何形状。当这些配体以[Pd(烯丙基)(X)]配合物(烯丙基= C3H5、1-CH3C3H4、1-C6H5C3H4、1,3-(C6H5)2C3H3; X = Cl,OAc)连接时,会发生单配位。通过[Pd(C3H5)(1)(Cl)]的X射线衍射确定的固态结构显示出烯丙基部分的非对称配位,这是由于亚磷酰胺配体相对于X-的较强反式影响所致。在所有这些配合物中,顺反异构体是溶液中存在的主要物质。由于顺式,顺式配合物的快速异构化和高反应性,烷基化后形成的主要产物是线性产物,特别是对于在卤化物抗衡离子存在下的单取代苯基烯丙基底物而言。但