Trichloromethanesulfonyl Chloride: A Chlorinating Reagent for Aldehydes
作者:Ciril Jimeno、Lidong Cao、Philippe Renaud
DOI:10.1021/acs.joc.5b02543
日期:2016.2.5
commercially available reagent, has been found to perform efficiently in the α-chlorination of aldehydes, including its catalytic asymmetric version, under very mild reaction conditions. Under our reaction conditions, this compound outperforms typical chlorinatingreagents for organic synthesis, facilitates workup and purification of the product, and minimizes the formation of toxic, chlorinated organic waste
已经发现三氯甲磺酰氯(CCl 3 SO 2 Cl),一种可商购的试剂,在非常温和的反应条件下,在醛的α-氯化反应中,包括催化的不对称形式,都能有效地进行醛的氯化反应。在我们的反应条件下,该化合物的性能优于用于有机合成的典型氯化试剂,有助于产品的后处理和纯化,并最大程度地减少了有毒的氯化有机废物的形成。
Mechanistic Studies on the Organocatalytic α‐Chlorination of Aldehydes: The Role and Nature of Off‐Cycle Intermediates
Herein we report the isolation and characterization of aminal intermediates in the organocatalytic α‐chlorination of aldehydes. These species are stable covalent ternary adducts of the substrate, the catalyst and the chlorinating reagent. NMR‐assisted kinetic studies and isotopic labeling experiments with the isolated intermediate did not support its involvement in downstream stereoselective processes
Stereoselective Synthesis of Chiral 4-(1-Chloroalkyl)-β-Lactams Starting from Amino Acids and Their Transformation into Functionalized Chiral Azetidines and Pyrrolidines
作者:Stijn Dekeukeleire、Matthias D’hooghe、Karl W. Törnroos、Norbert De Kimpe
DOI:10.1021/jo101220q
日期:2010.9.3
α-chlorination procedures. The latter aldehydes proved to be useful starting materials for the stereoselective Staudinger synthesis of (3S,4S)-4-[(1S)-1-chloroalkyl]azetidin-2-ones in high diastereomeric ratios and good overall yields, which were used as chiral building blocks for the preparation of a number of azetidines and pyrrolidines.
A general, enantioselective synthesis of 2-substituted thiomorpholines and thiomorpholine 1,1-dioxides
作者:Carson W. Reed、Craig W. Lindsley
DOI:10.1016/j.tetlet.2019.151104
日期:2019.10
In the course of our drug discovery programs, we had need to access chiral, 2-substituted thiomorpholines and their oxidized congeners, thiomorpholine 1,1-dioxides. Here, we disclose a high-yielding, general protocol for the enantioselective synthesis of C2-functionalized thiomorpholines and thiomorpholine 1,1-dioxides.
The enantioselective aminocatalytic α-chlorination of aldehydes is a challenging reaction because of its tendency to proceed through neutral intermediates in unselective pathways. Herein we report the rational shift to a highly selective reaction pathway involving charged intermediates using hexafluoroisopropanol as solvent. This change in mechanism has enabled us to match and improve upon the yields