Supercritical Carbon Dioxide: A Promoter of Carbon-Halogen Bond Heterolysis
作者:Thais Delgado-Abad、Jaime Martínez-Ferrer、Ana Caballero、Andrea Olmos、Rossella Mello、María Elena González-Núñez、Pedro J. Pérez、Gregorio Asensio
DOI:10.1002/anie.201303819
日期:2013.12.9
Amazing reaction medium: Supercritical carbon dioxide, with zero dipole moment, lower dielectric constant than pentane, and non‐hydrogen‐bonding behavior, ionizes carbon–halogen bonds, dissociates the resulting ion pairs, and escapes from capture by the carbocation intermediates at temperatures above 40 °C. These properties allow the observation of carbocation chemistry in the absence of acids.
Autocatalytic Friedel–Crafts Reactions of Tertiary Aliphatic Fluorides Initiated by B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>·H<sub>2</sub>O
作者:Marian Dryzhakov、Joseph Moran
DOI:10.1021/acscatal.6b00866
日期:2016.6.3
presence of other functional groups. Existing methods for the activation of tertiary aliphaticfluorides involve stoichiometric abstraction with fluorophilic Lewis acids or by Lewis-acid-catalyzed trapping with Si reagents. Herein, we describe a B(C6F5)3·H2O-catalyzed Friedel–Crafts reaction of tertiary alkyl fluorides that proceeds rapidly at room temperature without trapping reagents. The method is
C–F键是与碳最强的单键,构成存在其他官能团时选择性催化活化的固有挑战。现有的用于活化叔脂肪族氟化物的方法包括用亲氟路易斯酸或通过路易斯酸催化的硅试剂捕集的化学计量萃取。本文中,我们描述了叔烷基氟的B(C 6 F 5)3 ·H 2 O催化的Friedel-Crafts反应,该反应在室温下快速进行而没有捕获试剂。该方法适用于F完全选择性-在传统上更好的离去基团和显示器的自催化动力学特征。
[EN] TETRAKIS(DIMETHOXYPHENYL)ADAMANTANE (TDA) AND ITS INCLUSION COMPLEXES<br/>[FR] TÉTRAKIS(DIMÉTHOXYPHÉNYL)ADAMANTANE (TDA) ET SES COMPLEXES D'INCLUSION
申请人:RICHERT CLEMENS
公开号:WO2016139373A1
公开(公告)日:2016-09-09
Molecular storage materials for incorporating small molecules in solid matrices may find applications in structure elucidation, decontamination, and slow release of active ingredients. The syntheses of 1,3,5,7-tetrakis(2,4-dimethoxyphenyl)adamantane (TDA), 1,3,5,7-tetrakis(4-methoxyphenyl)adamantane, 1,3,5,7-tetrakis(4-methoxy-2-methylphenyl)adamantane, and 1,3,5,7-tetrakis(4-methoxy-2-ethylphenyl)adamantane are reported, together with details on their X-ray crystal structures. All four adamantanes crystallize readily. The octaether shows an unusual level of pseudopolymorphism in the solid state,and includes a wide range of different guest molecules in its crystal lattices. Thus far, 20 different inclusion complexes with guest molecules ranging from methanol or trifluorobenzene were characterized. Both nitromethane and benzene were taken up into inclusion materials and were shown to be released by one of three different processes.
A Unified Synthetic Strategy to Introduce Heteroatoms via Electrochemical Functionalization of Alkyl Organoboron Reagents
Based on systematic electrochemical analysis, an integrated synthetic platform of C(sp3)-based organoboron compounds was established for the introduction of heteroatoms. The electrochemically mediated bond-forming strategy was shown to be highly effective for the functionalization of sp3-hybridized carbon atoms with significant steric hindrance. Moreover, virtually all the nonmetallic heteroatoms could