ChemInform Abstract: A Stepwise Synthesis of Functionalized Calix(4)arenes and a Calix(6)arene with Alternate Electron-Withdrawing Substituents.

This article describes direct photoalkylation of electron-rich aromatic compounds with diazo compoiunds. C-2 alkylated indoles and pyrroles are obtained with good yields even though the photocatalyst (Ru(bpy)3Cl2) loading is as low as 0.075 mol %. For substrates bearing electron-withdrawing substituents the addition of a catalytic amount of N,N-dimethyl-4-methoxyaniline is required. Both EWG-EWG and EWG-EDG substituted diazo esters are suitable as alkylating agents. The reaction selectivity and mechanistic experiments suggest that carbenes/carbenoid intermediates are not involved in the reaction pathway, instead radical formation is proposed.

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Participation by some oxygen containing groups in hypobromous acid addition to double bond

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19833660 ◽

1983 ◽

Vol 48 (12) ◽

pp. 3660-3673 ◽

Cited By ~ 3

Author(s):

Pavel Kočovský

Keyword(s):

Double Bond ◽

Functional Groups ◽

Relative Reactivity ◽

Product Analysis ◽

Acid Addition ◽

Hypobromous Acid ◽

Electron Withdrawing Substituents

5(O)n and 6(O)π,n participations by some oxygen containing functional groups in the course of reaction with hypobromous acid have been studied on olefinic models of steroid type (I and II). The ability of these groups to participate has been compared on the basis of their relative reactivity with water (as externally attacking nucleophile) competing with participation. The results of the product analysis show that the ability to react with 5(O)n participation decreases in the order HO > CH3O ≃ CH3OCH2O > CH3CO2 > HCO2 > CH3SO3 ≥ (C2H5O)2PO2 > C6H5CO2 > O2NO ≫ CF3CO2, C2H5OCO2; in the last two functional groups is this ability completely suppressed. The 6(O)π,n participation comes in consideration only for compounds of the type II bearing the groups with the -X=O moiety which are ordered in the following sequence: C2H5OCO2 ≃ CH3CO2 ≥ (C2H5O)2PO2 > HCO2 > C6H5CO2. The remaining functional groups (CF3CO2, O2NO and CH3SO3do not undergo this process. Generally, it is valid that introduction of electron-withdrawing substituents into a participating group impedes or completely suppresses its ability to participate.

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Conjugated polymers containing pyrimidine with electron withdrawing substituents for organic photovoltaics with high open-circuit voltage

Polymer ◽

10.1016/j.polymer.2015.12.017 ◽

2016 ◽

Vol 83 ◽

pp. 50-58 ◽

Cited By ~ 6

Author(s):

Juae Kim ◽

Jihoon Lee ◽

Sangmin Chae ◽

Joo Young Shim ◽

Dal Yong Lee ◽

...

Keyword(s):

Conjugated Polymers ◽

Organic Photovoltaics ◽

Open Circuit Voltage ◽

Open Circuit ◽

Electron Withdrawing Substituents

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Synthetic, Spectroscopic, Structural, and Electrochemical Investigations of Ferricenium Derivatives with Weakly Coordinating Anions: Ion Pairing, Substituent, and Solvent Effects

Dalton Transactions ◽

10.1039/d1dt01192h ◽

2021 ◽

Author(s):

Firoz Shah Tuglak Khan ◽

Amy L Waldbusser ◽

Maria C. C. Carrasco ◽

Hadi Pourhadi ◽

Shabnam Hematian

Keyword(s):

Solvent Effects ◽

Ion Pairing ◽

Effective Strategy ◽

Weakly Coordinating Anions ◽

Weakly Coordinating ◽

Electron Withdrawing Substituents

A facile and effective strategy for the preparation of a series of ferricenium complexes bearing either electron-donating or electron-withdrawing substituents with weakly coordinating anions such as [B(C6F5)4]– or SbF6– is...

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Porphyrins. VIII. A stepwise synthesis of porphyrins

Australian Journal of Chemistry ◽

10.1071/ch9641157 ◽

1964 ◽

Vol 17 (10) ◽

pp. 1157 ◽

Cited By ~ 29

Author(s):

GM Badger ◽

RA Jones ◽

RL Laslett

Keyword(s):

Dicarboxylic Acid ◽

Stepwise Synthesis

1,2,3,4,5,6,7,8-Octanlethylporphin and α,γ,1,2,3,4,5,6,7,8-decamethylporphin have been prepared by the acid-catalysed condensation of 5,5'-diformyl-3,4,3',4'-tetramethylmethanes (VI; R = H or CH3) with the corresponding dicarboxylic acid derivatives (VII), followed by oxidation. For the preparation of meso-substituted porphyrins the method seems to be more satisfactory than those already in the literature, and can be developed further.

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