[EN] A SINGLE STEP ENANTIOSELECTIVE PROCESS FOR THE PREPARATION OF 3-SUBSTITUTED CHIRAL PHTHALIDES [FR] PROCÉDÉ ÉNANTIOSÉLECTIF EN UNE SEULE ÉTAPE POUR LA PRÉPARATION DE PHTALIDES CHIRAUX 3-SUBSTITUÉS
Novel compounds, their salts and compositions related thereto having activity against mammalian factor Xa are disclosed. The compounds are useful in vitro or in vivo for preventing or treating coagulation disorders.
P(<i>i</i>-PrNCH<sub>2</sub>CH<sub>2</sub>)<sub>3</sub>N: Efficient Catalyst for Synthesizing β-Hydroxyesters and α,β-Unsaturated Esters using α-Trimethylsilylethylacetate (TMSEA)
作者:Kuldeep Wadhwa、John G. Verkade
DOI:10.1021/jo900477q
日期:2009.6.5
We present an efficient synthesis of β-hydroxyesters and α,β-unsaturatedesters via activation of the silicon−carbon bond of α-trimethylsilylethylacetate using catalytic amounts of the commercially available P(i-PrNCH2CH2)3N 1a. Selectivity for either of these two products can be achieved simply by altering the catalyst loading and reaction temperature to afford addition or stereoselective condensation
我们提出了通过使用催化量的市售P(i- PrNCH 2 CH 2)3 N 1a活化α-三甲基甲硅烷基乙酸乙酯的硅碳键来有效合成β-羟基酯和α,β-不饱和酯的方法。通过改变催化剂的加入量和反应温度以提供加成或立体选择性缩合,可以简单地实现对这两种产物中任一种的选择性。这种方法比较温和,可以耐受各种各样的官能团。
The One-Pot Wittig Reaction: A Facile Synthesis of α,β-Unsaturated Esters and Nitriles by Using Nanocrystalline Magnesium Oxide
作者:Boyapati M. Choudary、Koosam Mahendar、M. Lakshmi Kantam、Kalluri V. S. Ranganath、Taimur Athar
DOI:10.1002/adsc.200606001
日期:2006.9
Nanocrystalline magnesium oxide was found to be an effective heterogeneous, solid base catalyst for the one-pot Wittig reaction to afford α,β-unsaturatedesters and nitriles in excellent yields with high E-stereoselectivity in the presence of triphenylphosphine under mild conditions.
A highly efficient version of the palladium-catalysed arylation of alkenes with aryl bromides
作者:Alwyn Spencer
DOI:10.1016/0022-328x(83)89511-4
日期:1983.11
The palladium-catalysed arylation of alkenes with aryl bromides or iodides is shown to proceed in high yields at very low palladium concentration when carried out in a suitable strongly polar solvent with a carboxylate anion as base. The preferred combination is N, N-dimethylformamide with sodium acetate. The reaction is markedly dependent on the substituents in the aryl bromide, being favoured by
CN-assisted oxidative cyclization of cyano cinnamates and styrene derivatives: a facile entry to 3-substituted chiral phthalides
作者:R. Santhosh Reddy、I. N. Chaithanya Kiran、Arumugam Sudalai
DOI:10.1039/c2ob25409c
日期:——
of o-cyano cinnamates and styrene derivatives leads to efficient construction of chiralphthalide frameworks in high optical purities. This unique reaction is characterized by unusual synergism between CN and osmate groups resulting in rate enhancement of the AD process. The method is amply demonstrated by the synthesis and the structural/stereochemical assignment of the natural products.