Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
作者:Eloi P Coutant、Vincent Hervin、Glwadys Gagnot、Candice Ford、Racha Baatallah、Yves L Janin
DOI:10.3762/bjoc.14.264
日期:——
We have explored here the scope of the age-old diethyl malonate-based accesses to α-aminoesters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered
Palladium-Catalyzed Oxidative Carbonylation of Alkyl and Aryl Indium Reagents with CO under Mild Conditions
作者:Yingsheng Zhao、Liqun Jin、Peng Li、Aiwen Lei
DOI:10.1021/ja801116s
日期:2008.7.1
CO now can react with organoindium reagents. A novel palladium-catalyzed oxidative carbonylation reaction of organoindium reagents by CO gas with desyl chloride as oxidant was developed in supplementation with the classical methods for preparation of carboxylic acid derivatives. Primary, secondary alkyl indium reagents with beta-hydrogens and aryl indium reagents were suitable substrates, and the reaction
CO 现在可以与有机铟试剂反应。在补充制备羧酸衍生物的经典方法的基础上,开发了一种新的钯催化的有机铟试剂氧化羰基化反应,以 CO 气体和脱磺酰氯为氧化剂。带有β-氢的一级、二级烷基铟试剂和芳基铟试剂是合适的底物,反应可以在60摄氏度和50 psi CO下进行。烷基铟试剂的羰基化可以在没有额外碱的情况下顺利进行。虽然铟试剂是由相应的格氏试剂(在低温下)制备的,但它们在质子反应条件下显示出与各种官能团的完全相容性。包括化学计量和催化反应检查在内的初步机理研究提供了支持该机理的运行的证据,该机理包括将去甲酰氯氧化加成到 Pd(0) 和快速互变异构化得到钯烯醇化物物质 II (ROPdCl),烯醇化物基团在 Pd(0) 中的置换。 II 由 R(2)OH 插入,然后插入 CO 得到烷氧基羰基钯配合物 V,该配合物与 R(1)(3)In 进行金属转移和还原消除,得到产物和 Pd(0) 物质。在这种机
Enantioselective protonation of samarium enolates by a C2-symmetric chiral diol
High enantioselectivity (up to 97%ee) have been achieved in the protonation of samarium enolates which were generated by SmI2-mediated cross-coupling reaction between unsymmtrical dialkylketene and allyl iodide, using a C-2-symmetric chiral diol as a proton source. The stereochemistry of enolate formation and of the enantioselective protonation is discussed.
The Synthesis of Condensed Polynuclear Hydrocarbons by the Cyclodehydration of Aromatic Alcohols. I. Indanes
作者:Marston T. Bogert、David Davidson
DOI:10.1021/ja01316a060
日期:1934.1
Julia et al., Bulletin de la Societe Chimique de France, 1959, p. 1449,1452