Micellar effects in the nitrous acid deamination reaction of (R)-[1-2H]-1-octanamine
摘要:
The nitrous acid deamination of 1-octanamine (1) afforded mixtures of isomeric octenes, octanols, and octyl nitrites. The aggregation of 1.HClO4 in micelles induced the formation of dioctyl ethers and of 1-nitrooctane as additional products. In homogeneous solution (submicellar aqueous conditions or HOAc), [1-H-2]-1-octanol was obtained from [1-H-2]-1 with ca. 95% inversion of configuration. Above the critical micelle concentration, the enantiomeric purity of [1-H-2]-1-octanol decreased while [1-H-2]-1-nitrooctane was formed with ca.90% retention of configuration. 1-Octyl..NO2 radical pairs, rather than ion pairs, are likely to intervene on the retentive route to 1-nitrooctane and 1-octyl nitrite. Equilibration, via NO exchange, of (R)-[1-H-2]-1-octyl nitrite with the more abundant (S)-[1-H-2]-1-octanol is thought to account for the diminished ee of both products.
Enantioselective Synthesis of (<i>R</i>)- and (<i>S</i>)-1-<sup>2</sup>H-1-Octanol and Their Corresponding Amines
作者:Diederik W. R. Balkenende、Seda Cantekin、Christopher J. Duxbury、Marcel H. P. van Genderen、E. W. Meijer、Anja R. A. Palmans
DOI:10.1080/00397911.2010.527422
日期:2012.2.15
provided a one-step procedure from a commercially available starting compound to both enantiomers of 1-2H-1-octanol in good yields (>80%) and good enantiomeric excess (∼97%). The (S)-alcohols were converted to their corresponding (R)-amines, which showed ee's around 90%. GRAPHICAL ABSTRACT
A new chiral catalyst for the enantioselective synthesis of secondary alcohols and deuterated primary alcohols by carbonyl reduction
作者:E.J. Corey、John O. Link
DOI:10.1016/s0040-4039(01)93871-7
日期:1989.1
efficient synthesis of(S)-(−)-2-(di-β-naphthylhydroxymethyl)pyrrolidine (1) makes available the oxazaborolidine derivatives2 and3 which are excellent catalysts for borane reduction of a variety of achiral ketones to chiral secondary alcohols, e.g. acetophenone, 98% ee; α-tetralone, 95% ee; and methyl-4-oxo-4-phenyl butyrate, 96% ee. The synthesis of chiral 1-deuterio primary alcohols fromachiral aldehydes
Enantiopure Chiral (2,4,6-Triisopropylbenzoyl)oxy-[D<sub>1</sub>]methyllithium: Configurational Stability, Reactions, and Mechanistic Studies
作者:Dagmar C. Kapeller、Friedrich Hammerschmidt
DOI:10.1021/jo802625q
日期:2009.3.20
The configurationalstability of enantiopure chiral (2,4,6-triisopropylbenzoyl)oxy-[D1]methyllithium generated by a tin−lithium exchange was tested on the macroscopic time scale, employing trapping experiments with benzaldehyde. It was found to be configurationally stable for minutes at −78 °C and to be an appropriate substitute for the carbamoyloxy-substituted analogue in terms of cleavage. Its addition
在宏观时间尺度上测试了由锡-锂交换产生的对映纯手性(2,4,6-三异丙基苯甲酰基)氧基-[D 1 ] 甲基锂的构型稳定性,采用苯甲醛捕获实验。发现它在 -78 °C 下构型稳定数分钟,并且在裂解方面是氨基甲酰氧基取代类似物的合适替代品。研究了将其添加到几种亲电子试剂中,从而得出了制备手性伯氘化醇的方案,例如合成 2-苯基-[1-D 1]98% 对映体过量 (ee) 的乙醇。此外,通过标记底物的光谱研究解决了这种芳酰氧基甲基锂的对映异构化和分解机制。它通过形成乙烯(次要途径)和n- BuLi同系化最多三个亚甲基单元而分解,然后交换为 Bu 4 Sn的丁基。
Configurational Stability of Oxymethyllithiums as Intermediates in Intramolecular Rearrangements
作者:Dagmar C. Kapeller、Lothar Brecker、Friedrich Hammerschmidt
DOI:10.1002/chem.200701054
日期:2007.11.26
were tested for their microscopic configurational stability in intramolecular isomerizations, such as the silyl- and germyl-[1,2]-retro-Brook and the sigmatropic[2,3]-Wittig rearrangement. The influence of temperature, solvent, and migrating group on the stability of the intermediate carbanions was studied. Furthermore, the stereochemical course of these rearrangements was elucidated, resulting in highly