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。
Mechanistically Guided Design of an Efficient and Enantioselective Aminocatalytic α-Chlorination of Aldehydes
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
of the starting aldehydes was involved in this asymmetricfluorination. This paper describes the determination of the absolute stereochemistry of a resulting alpha-chloro-alpha-fluoroaldehyde. Some information about the substrate scope and a possible reaction mechanism are also described which shed more light on the nature of this asymmetricfluorination reaction.
Enantioselective α-Chlorination of Aldehydes with Recyclable Fluorous (S)-Pyrrolidine-Thiourea Bifunctional Organocatalyst
作者:Chun Cai、Wei Zhang、Liang Wang、Dennis Curran
DOI:10.1055/s-0029-1219198
日期:2010.2
A novel fluorous (S)-pyrrolidine-thiourea bifunctional organocatalyst is prepared. The catalyst shows good activity and enantioselectivity for direct α-chlorination of aldehydes using N-chlorosuccinimide (NCS) as the chlorine source. It can be recovered from the reaction mixture by fluorous solid-phase extraction with excellent purity for direct reuse.
Stereodivergent Synthesis of Enantioenriched γ‐Butyrolactones Bearing Two Vicinal Stereocenters Enabled by Synergistic Copper and Iridium Catalysis
作者:Lu Xiao、Liang Wei、Chun‐Jiang Wang
DOI:10.1002/anie.202107418
日期:2021.11.15
bearing two vicinal stereocenters are accessible with excellent diastereoselective and enantioselective control. The chiral IrIII -π-allyl intermediate was separated and characterized to understand the origin of the regio- and stereoselectivity of the initial C-Cbondformation process. Control experiments shed some light on the catalyst/substrate and catalyst/catalyst interactions in this dual catalytic
凭借作为双原子合成子的偶氮甲碱叶立德的全新反应模型,我们展示了通过协同 Cu/Ir 催化的不对称级联烯丙基化/内酯化以及 γ 的所有四种立体异构体立体发散制备 γ-丁内酯的第一个例子带有两个邻位立体中心的丁内酯可通过出色的非对映选择性和对映选择性控制获得。手性 IrIII -π-烯丙基中间体被分离和表征,以了解初始 CC 键形成过程的区域选择性和立体选择性的起源。对照实验揭示了这种双催化系统中催化剂/底物和催化剂/催化剂相互作用,以合理化具有不同催化剂组合的相关动力学/动态动力学拆分过程。