Asymmetric Friedel–Crafts alkylation of indoles with 2-nitro-3-arylacrylates catalyzed by a metal-templated hydrogen bonding catalyst
摘要:
An asymmetric Friedel-Crafts alkylation of indoles with 2-nitro-3-arylacrylates catalyzed by a metal-templated hydrogen bonding catalyst has been established. The asymmetric induction relies on chirality transfer solely from the octahedral metal stereocenter via three weak hydrogen bonds. All the products are provided with good to excellent enantioselectivities while modest diastereoselectivities, which can be converted into a variety of valuable indole-containing chiral building blocks including tryptophan derivatives. (C) 2015 Elsevier Ltd. All rights reserved.
Zn-Catalyzed Enantio- and Diastereoselective Formal [4 + 2] Cycloaddition Involving Two Electron-Deficient Partners: Asymmetric Synthesis of Piperidines from 1-Azadienes and Nitro-Alkenes
作者:John C. K. Chu、Derek M. Dalton、Tomislav Rovis
DOI:10.1021/jacs.5b00033
日期:2015.4.8
We report a catalytic asymmetricsynthesis of piperidines through [4 + 2] cycloaddition of 1-azadienes and nitro-alkenes. The reaction uses earth abundant Zn as catalyst and is highly diastereo- and regioselective. A novel BOPA ligand (F-BOPA) confers high reactivity and enantioselectivity in the process. The presence of ortho substitution on the arenes adjacent to the bis(oxazolines) was found to
Synthesis of highly modular bis(oxazoline) ligands by Suzuki cross-coupling and evaluation as catalytic ligands
作者:Xavier Cattoën、Miquel A. Pericàs
DOI:10.1016/j.tet.2009.07.053
日期:2009.9
New bis(oxazoline) ligands (BOXs) containing biaryl substitutents at the C-4 position and H or CH2OR substituents at the C-5 position have been synthesized using Suzuki cross-coupling as the main tool for structural diversity. Copper, zinc, and palladium complexes of the prepared BOXs have been evaluated in the following catalytic asymmetric processes: Acylation with kinetic resolution of trans-1,2-cyclohexanediol
Synthesis of Chiral o-Aminobenzylamines by Stereoselective Addition of Grignard Reagents to N-[(o-Aminophenyl)methylene] sulfinamides
作者:Wei Zhou、Xianqiang Zhong、Guorong Xiao
DOI:10.1055/a-1423-5679
日期:2021.6
Chiral o-aminobenzylamines are synthons for many chiral ligands and catalysts that have been widely used in asymmetric synthesis. Here, we report a highly efficient and stereoselective addition of Grignard reagents to N-[(o-aminophenyl)methylene]sulfinamides to give a range of o-aminosulfinylimines in good yields with good to excellent diastereoselectivities.