- Indoline Catalyzed Acylhydrazone/Oxime Condensation under Neutral Aqueous Conditions
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Acylhydrazones formation has been widely applied in materials science and biolabeling. However, their sluggish condensation rate under neutral conditions limits its application. Herein, indolines with electron-donating groups are reported as a new catalyst scaffold, which can catalyze acylhydrazone, hydrazone, and oxime formation via an iminium ion intermediate. This new type of catalyst showed up to 15-fold rate enhancement over the traditional anilinecatalyzed reaction at neutral conditions. The identified indoline catalyst was successfully applied in hydrogel formation.
- Zhou, Yuntao,Piergentili, Irene,Hong, Jennifer,Helm, Michelle P. Van Der,MacChione, Mariano,Li, Yao,Eelkema, Rienk,Luo, Sanzhong
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supporting information
p. 6035 - 6040
(2020/10/02)
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- Reversible photo-gated transmembrane channel assembled from an acylhydrazone-containing crown ether triad
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We have prepared a crown ether triad containing acylhydrazone units. In solution, the triad can self-assemble linearly to form an organogel. UV light-induced E/Z isomerization of the C=N bond of the acylhydrazone unit endows the assembly with photo-sensit
- Zhou, Yan,Chen, Yong,Zhu, Ping-Ping,Si, Wen,Hou, Jun-Li,Liu, Yu
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supporting information
p. 3681 - 3684
(2017/04/03)
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- A flexible solution to anion transport: Powerful anionophores based on a cyclohexane scaffold
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Transmembrane anion carriers (anionophores) have potential for biological activity, including the treatment of channelopathies such as cystic fibrosis. A new family of anionophores has been synthesized, in which three thiourea groups are mounted on a cyclohexane-based scaffold. Though conceptually related to earlier polycyclic systems, these molecules are simpler and far more accessible. Preorganization is somewhat reduced compared to earlier systems, and anion affinities are correspondingly lower. However, transport activities set new records. This surprising performance suggests a role for controlled flexibility in the design of transmembrane anion carriers. Speedy shuttling: New anionophores were developed which are simpler and far more accessible than conceptually related earlier systems. They are also less preorganized and anion affinities are lower (as expected), but transport activities set new records. This surprising performance suggests a role for controlled flexibility in the design of transmembrane anion carriers.
- Cooper, James A.,Street, Steven T. G.,Davis, Anthony P.
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supporting information
p. 5609 - 5613
(2014/06/10)
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- A conformational study of cyclohexane-1,3,5-tricarbonitrile derivatives
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Cyclohexane-1,3,5-tricarbonitrile reached equilibrium having 1,3-cis-1,5-cis and 1,3-cis-1,5-trans isomers in a ratio of 3:7. The cis,cis-isomer preferred the conformation with three equatorial cyano groups, whereas the cis,trans-isomer displayed two cyano groups on equatorial positions and another cyano group on axial position. Condensation of cis,cis-cyclohexane-1,3,5-tricarbonitrile with L-(S)-valinol by the catalysis of ZnCl2 in refluxing 1,2-dichlorobenzene afforded two isomeric cyclohexane-1,3,5-trioxazolines in favor of the 1,3-cis-1,5-trans isomer. Metalation of cis,cis-cyclohexane-1,3,5-tricarbonitrile, followed by alkylations with dimethyl sulfate, benzyl bromide or allyl bromide, gave the corresponding trialkylation products with predominance of 1,3-cis-1,5-trans isomers. The cis,trans-isomer showed two cyano groups on axial positions and another cyano group on equatorial position, whereas the cis,cis-isomer exhibited three axial cyano groups. Treatment of trimethyl cis,cis-cyclohexane-1,3,5-tricarboxylate with lithium diisopropylamide and dimethyl sulfate afforded mainly the trimethyl ester of Kemp's triacid, which showed three axial carboxylate groups. Two competitive factors, i.e. the steric effect of incoming electrophiles and the dipole-dipole interactions of the cyano or carboxylate groups, might interplay to give different stereoselectivities in these reaction systems.
- Chuang, Tsung-Hsun,Fang, Jim-Min
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p. 193 - 200
(2007/10/03)
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- Synthesis of 3,5,12-Triazawurtzitanes ( 3,5,12-Triazatetracyclo2,604,9>dodecanes
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The first examples of 3,5,12-triazawurtzitanes (3,5,12-triazatetracyclo2,604,9>dodecanes are described. cis, cis - 1.3.5-Triformylcyclohexane (8) has been synthesised by Swern oxidation of cis, cis - 1.3.5-tris(hydroxymethyl
- Nielsen, Arnold T.,Christian, Stephen L.,Moore, Donald W.,Gilardi, Richard D.,George, Clifford F.
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p. 1656 - 1662
(2007/10/02)
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