Isolable Chiral Aggregates of Achiral π-Conjugated Carboxylic Acids.

08:38 EDT 31st March 2015 | BioPortfolio

Summary of "Isolable Chiral Aggregates of Achiral π-Conjugated Carboxylic Acids."

The induced aggregation of achiral building blocks by a chiral species to form chiral aggregates with memorized chirality has been observed for a number of systems. However, chiral memory in isolated aggregates of achiral building blocks remains rare. One possible reason for this discrepancy could be that not much is understood in terms of designing these chiral aggregates. Herein, we report a strategy for creating such isolable chiral aggregates from achiral building blocks that retain chiral memory after the facile physical removal of the chiral templates. This strategy was used for the isolation of chiral homoaggregates of neutral achiral π-conjugated carboxylic acids in pure aqueous solution. Under what we have termed an "interaction-substitution" mechanism, we generated chiral homoaggregates of a variety of π-conjugated carboxylic acids by using carboxymethyl cellulose (CMC) as a mediator in acidic aqueous solutions. These aggregates were subsequently isolated from the CMC templates whilst retaining their memorized supramolecular chirality. Circular dichroism (CD) spectra of the aggregates formed in the acidic CMC solution exhibited bisignated exciton-coupled signals of various signs and intensities that were maintained in the isolated pure homoaggregates of the achiral π-conjugated carboxylic acids. The memory of the supramolecular chirality in the isolated aggregates was ascribed to the substitution of COOH/COOH hydrogen-bonding interaction between the carboxylic acid groups within the aggregates for the hydrogen-bonding interactions between the COOH groups of the building blocks and the chiral templates. We expect that this "interaction-substitution" procedure will open up a new route to isolable pure chiral aggregates from achiral species.


Department of Chemistry, College of Chemistry and Chemical Engineering and the MOE Key Laboratory of Analytical Sciences, Xiamen University, Xiamen 361005 (P. R. China), Fax: (+86) 592-218-6401.

Journal Details

This article was published in the following journal.

Name: Chemistry (Weinheim an der Bergstrasse, Germany)
ISSN: 1521-3765
Pages: 3631-6


PubMed Articles [5072 Associated PubMed Articles listed on BioPortfolio]

A combination of the "pillaring" strategy and chiral induction: an approach to prepare homochiral three-dimensional coordination polymers from achiral precursors.

Utilizing enantiopure camphorsulfonic acid as a chiral induction agent, 3D homochiral complexes were obtained from achiral 2D layers and MoO4(2-) pillars. This methodology combines the "pillaring" str...

Chiral self-sorting and amplification in isotropic liquids of achiral molecules.

According to our present knowledge, the spontaneous resolution of racemic mixtures of chiral molecules or chiral conformers of achiral molecules into macroscopic chiral superstructures requires the co...

Direct Enantioselective Conjugate Addition of Carboxylic Acids with Chiral Lithium Amides as Traceless Auxiliaries.

Michael addition is one of premier synthetic methods for carbon-carbon and carbon-heteroatom bond formation. Using chiral dilithium amides as traceless stereodirecting auxiliaries, we report direct Mi...

Systematic methodology for the development of biocatalytic hydrogen-borrowing cascades: application to the synthesis of chiral α-substituted carboxylic acids from α-substituted α,β-unsaturated aldehydes.

Ene-reductases (ERs) are flavin dependent enzymes that catalyze the asymmetric reduction of activated carbon-carbon double bonds. In particular, α,β-unsaturated carbonyl compounds (e.g. enals and en...

Rh(III)-Catalyzed Decarboxylative ortho-Heteroarylation of Aromatic Carboxylic Acids by Using the Carboxylic Acid as a Traceless Directing Group.

Highly selective decarboxylative ortho-heteroarylation of aromatic carboxylic acids with various heteroarenes has been developed through Rh(III)-catalyzed two-fold C-H activation, which exhibits a wid...

Clinical Trials [376 Associated Clinical Trials listed on BioPortfolio]

A Study to Investigate Effects of Omega-3 Carboxylic Acids and Dapagliflozin on Liver Fat Content in Diabetic Patients

This study is a double-blind randomized, placebo-controlled, parallel-group, 12 week study performed in up to 5 centres in Sweden to assess the effect of Omega-3 carboxylic acids and dapag...

Platelet Leukocyte Aggregates in Acute Cardiac Syndrome vs Healthy Volunteers

This project aims to refine previous studies including the investigators work recently published in August 2012 Journal Thrombosis and Thrombolysis. That study showed a relationship betwee...

The Health Benefits of Conjugated Linoleic Acid (CLA) for Asthma & Allergy

Conjugated linoleic acids (CLA) are naturally occurring free fatty acids derived from the tissues and milk of ruminant animals such as cows. CLA has multiple biological properties includin...

Dietary Fatty Acids as Complementary Therapy in Type 2 Diabetes Mellitus

The purpose of the study is to see how a dietary oil called conjugated linoleic acid, or CLA, might be useful in combination with diabetes medication. Some studies show that CLA can modes...

Study Evaluating The Effects Of Bazedoxifene/Conjugated Estrogens On Endometrial Safety And Postmenopausal Osteoporosis

The purpose of this research study is to evaluate the safety and effectiveness of this investigational drug for the treatment of menopausal symptoms while protecting the endometrium (uteri...

Medical and Biotech [MESH] Definitions

Organic compounds containing the carboxy group (-COOH). This group of compounds includes amino acids and fatty acids. Carboxylic acids can be saturated, unsaturated, or aromatic.

Enzymes which catalyze the hydrolysis of carboxylic acid esters with the formation of an alcohol and a carboxylic acid anion.

Compounds consisting of chains of AMINO ACIDS alternating with CARBOXYLIC ACIDS via ester and amide linkages. They are commonly cyclized.

Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.

Carboxylic acids that have open-chain molecular structures as opposed to ring-shaped structures.

Search BioPortfolio:

Searches Linking to this Article