cycloaddition of β-substituted ene- and thioenecarbamates as well as cyclic enamides with quinone diimides catalyzed by a BINOL- and SPINOL-derived phosphoric acid is reported. A wide variety of 2,3-disubstituted 2-aminoindolines, including polycyclic ones, were prepared in generally high yields (up to 98%) with moderate to complete diastereoselectivities and in most cases excellent enantioselectivities
Preparation, characterization and application of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2]·2Cl) as an efficient dicationic ionic catalyst for the N-Boc protection of amines
In this work, 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2]·2Cl), as a novel Brönsted acidic ionic catalyst is synthesized and characterized using a series of techniques including FT-IR, TGA, DTA, SEM, pH analysis and Hammett acidity function. This substance can significantly catalyze the N-Boc protection of amines without solvent interference at room temperature. The advantages of this
Visible-Light-Mediated Nitration of Protected Anilines
作者:Simon J. S. Düsel、Burkhard König
DOI:10.1021/acs.joc.7b03260
日期:2018.3.2
The photocatalytic nitration of protected anilines proceeds with riboflavin tetraacetate as an organic photoredox catalyst. Sodium nitrite serves as the NO2 source in this visible-light-driven room temperature reaction. Various nitroanilines are obtained in moderate to good yields without the addition of acid or stoichiometric oxidation agents. The catalytic cycle is closed by aerial oxygen as the
A Diaminopillar[5]arene‐Based Macro‐Bicyclic Molecule: Synthesis, Characterization and A Lock‐Key Story
作者:Weibo Hu、Zhuo Wang、Xiao-Li Zhao、Yahu A. Liu、Jiu-Sheng Li、Biao Jiang、Ke Wen
DOI:10.1002/chem.201804950
日期:——
A new macrobicyclic molecule (BC‐DAP5), consisting of a diaminopillar[5]arene cavity and a fused ring, was successfully constructed using a Grubbs metathesis reaction. Further studies indicated that BC‐DAP5 possessed a unique molecular behavior, showing a response to acid/base stimuli. In BC‐DAP5, protons (acid) acted as a lock, locking the fused ring out of the cavity (pillar[5]arene), and a base
Practical Access to meta‐Substituted Anilines by Amination of Quinone Imine Ketals Derived from Anisidines: Efficient Synthesis of Anti‐Psychotic Drugs
is reported based on a one-pot procedure. The strategy is based on direct C−N bond formation for the practicalsynthesis of meta-substituted anilines, thus reversing the conventional site-selectivity. A concise and efficientsynthesis of anti-psychotics and in particular of anti-schizophrenic drugs is shown.