Racemic α-acyloxyalkylphosphonates (±)-4 are prepared and tested for kinetic resolution by lipases AP 6 and to a minor extent by F-AP 15. The former proves to be a useful enzyme in terms of broadness of application, reaction rate and enantiomeric excess. Lipase F-AP 15 transformed neither of the two substrates checked for hydrolysis. Enzymatic hydrolysis of α-acyloxyphosphonates containing straight chain alkyl groups with lipase AP 6 yields (S)-α-hydroxyalkylphosphonates 3 preferentially. Substrates with branched chain alkyl groups are hydrolysed with lower enantioselectivity, the (R)-ester being saponified more easily than the (S)-ester.
制备了外消旋δ-±-乙酰氧基烷基膦酸盐 (±)-4,并通过脂肪酶 AP 6 和少量 F-AP 15 进行了动力学解析测试。前者在应用广泛性、反应速度和对映体过量方面被证明是一种有用的酶。脂肪酶 F-AP 15 对两种底物都没有进行水解转化。用脂肪酶 AP 6 对含有直链烷基的 δ-acyloxyphosphonates 进行酶水解,可优先生成 (S)-δ-hydroxyalkylphosphonates 3。含有支链烷基的底物水解的对映选择性较低,(R)-酯比(S)-酯更容易被皂化。
Amido rare-earth complexes supported by an ansa bis(amidinate) ligand with a rigid 1,8-naphthalene linker: synthesis, structures and catalytic activity in rac-lactide polymerization and hydrophosphonylation of carbonyl compounds
作者:Marina V. Yakovenko、Natalia Yu. Udilova、Tatyana A. Glukhova、Anton V. Cherkasov、Georgy K. Fukin、Alexander A. Trifonov
DOI:10.1039/c4nj01698j
日期:——
A synthetic approach to rare-earth amido complexes coordinated by an ansa bis(amidinate) ligand with a 1,8-naphthalene linker was developed and allowed for the synthesis of a series of complexes [1,8-C10H6NC(tBu)N-2,6-Me2C6H3}2]LnN(SiMe3)2(THF)n (Ln = Y, n = 0 (2); Ln = Sm, n = 1 (3); Ln = Nd, n = 1 (4)) in reasonable yields. Complexes 2–4 initiate ring-opening polymerization (ROP) of rac-lactide
开发了一种由ansa双(ami酰胺)配体与1,8-萘连接基配位的稀土酰胺配合物的合成方法,该方法可用于合成一系列配合物[1,8-C 10 H 6 NC(t Bu)N-2,6-Me 2 C 6 H 3 } 2 ] LnN(SiMe 3)2(THF)n(Ln = Y,n = 0(2); Ln = Sm,n = 1(3) ; Ln = Nd,n = 1(4)),且产率合理。配合物2-4引发外消旋丙交酯的开环聚合(ROP),并使100-250当量完全转化。25°C下60–90分钟内的单体数量。所获得的聚丙交酯具有无规结构和中等分子量分布(M w / M n = 1.30–2.12)。发现由于缓慢的起始阶段,所获得的聚合物的实验M n值明显高于所计算的M n值。丙交酯具有3–5当量的有效不朽ROP。使用配合物2-4作为催化剂进行每个金属中心的异丙醇分析。系统2-4/ iPrOH在ROP中表现出更高
A Facile Synthesis of Diethyl 1-(Phenylthio)alkylphosphonates
作者:Tadeusz Gajda
DOI:10.1055/s-1988-33435
日期:——
The title compounds have been obtained in moderate yields by the reaction of diethyl 1-hydroxyalkylphosphonates with thiophenol in the presence of the triphenylphosphine/diethyl azodicarboxylate system.
An efficient protocol for the hydrophosphonylation of aromatic and aliphatic aldehydes catalyzed by PS-BEMP under solvent-free conditions (SolFC) has been reported. Addition reactions were performed by using equimolar amounts of reagents and the resulting α-hydroxyphosphonates were isolated with simple workup procedures. A large scale protocol for the preparation of a representative α-hydroxyphosphonate
Synthesis and Characterization of Organolanthanide Complexes with a Calix[4]-pyrrolyl Ligand and Their Catalytic Activities toward Hydrophosphonylation of Aldehydes and Unactivated Ketones
The alkali metal salt free dinuclear trivalent lanthanide amido complexes (eta(5):eta(1):eta(5):eta(1)-Et-8-calix[4]-pyrrolyl)LnN-(SiMe3)(2)}(2) (Ln = Nd (2), Sm (3), Gd (4)) were prepared through the silylamine elimination reactions of calix[4]-pyrrole [Et2C(C4H2NH)](4) (1) with 2 equiv of [(Me3Si)(2)N](3)Ln(mu-Cl)Li(THF)(3) (Ln = Nd, Sm, Gd) in toluene at 110 degrees C. The complexes were fully characterized by elemental, spectroscopic, and single-crystal X-ray analyses. Studies on the catalytic activity of the new lanthanide amido complexes revealed that these complexes can be used as efficient catalysts for hydrophosphonylation of aldehydes and unactivated ketones, affording the products in high yields by employing a low catalyst loading (0.1 mol %) at room temperature in a short time (20 min). Noteworthy is that it is the first application of calix[4]-pyrrolyl-supported lanthanide amides as catalysts to catalyze the hydrophosphonylation of aldehydes and unactivated ketones under mild conditions.