A new ring for your indole: An unprecedented copper‐catalyzed enantioselectiveFriedel–Craftsalkylation/N‐hemiacetalization cascade reaction with indoles and β,γ‐unsaturated α‐ketoesters is reported. This mild strategy provides new access to various synthetically and biologically important 2,3‐dihydro‐1H‐pyrrolo[1,2‐a]indoles in a highlyenantioselective manner.
吲哚的新环:据报道,铜与吲哚和β,γ-不饱和α-酮酸酯发生了前所未有的铜催化对映选择性Friedel-Crafts烷基化/ N-半缩醛化级联反应。这种温和的策略以高度对映选择性的方式为各种合成和生物学上重要的2,3-二氢-1 H-吡咯并[1,2- a ]吲哚提供了新途径。
Chiral N-heterocyclic carbene-catalyzed generation of ester enolate equivalents from α,β-unsaturated aldehydes for enantioselective Diels–Alder reactions
作者:Juthanat Kaeobamrung、Marisa C. Kozlowski、Jeffrey W. Bode
DOI:10.1073/pnas.1007469107
日期:2010.11.30
The catalytic generation of chiral ester enolate equivalents from alpha,beta-unsaturated aldehydes with chiral N-hetereocyclic carbene catalysts makes possible highly enantioselective hetero-Diels-Alder reactions. The reactions proceed under simple, mild conditions with both aliphatic and aromatic substituted enals as substrates. Previous attempts to employ these starting materials as enolate precursors
Highly Enantioselective Synthesis of 3,4-Dihydropyrans through a Phosphine-Catalyzed [4+2] Annulation of Allenones and β,γ-Unsaturated α-Keto Esters
作者:Weijun Yao、Xiaowei Dou、Yixin Lu
DOI:10.1021/ja5109358
日期:2015.1.14
A phosphine-catalyzed novel [4+2] annulation process was devised employing allene ketones as C2 synthons and β,γ-unsaturated α-keto esters as C4 synthons. In the presence of an L-threonine-derived bifunctional phosphine, 3,4-dihydropyrans were obtained in high yields and with virtually perfect enantioselectivities. The synthetic value of the dihydropyran motif was demonstrated by a concise preparation
Enantioselective Copper-Catalyzed Conjugate Addition of Trimethylaluminium to β,γ-Unsaturated α-Ketoesters
作者:Ludovic Gremaud、Alexandre Alexakis
DOI:10.1002/anie.201107324
日期:2012.1.16
Not a cop out: The copper‐catalyzed asymmetric conjugateaddition of organometallic reagents to Michael acceptors is an important methodology for forming a CC bond in an enantioselective manner. Such an addition of Me3Al to β,γ‐unsaturatedα‐ketoesters is described to proceed in high yield and selectivity. CuTC=copper(I) thiophene‐2‐carboxylate.
We report herein the enantioselectiveCu-catalyzed conjugate addition of organometallic reagents to sensitive Michael acceptors and their application to the synthesis of relevant target molecules. This is one of the most important methodologies to form a C-C bond in an enantioselective manner. A wide range of alpha,beta-unsaturated aldehydes and beta,gamma-unsaturated-alpha-ketoesters has been successfully