Synthesis of enantiomerically enriched benzimidazole-triazoles: Application as organocatalyst for asymmertric Diels-Alder reaction

93-1014-(Benzimidazolylmethyl)-1,2,3-triazole derivatives 8a-g and 9a-g have been developed using click chemistry protocol in regioselective manner and in high yields. These compounds have geometry to behave as chiral tweezers due to the presence of flexibly bound pi-rich hetero-aryl rings in addition to a chiral center. The synthesized chiral benzimidazole-triazoles have been found to be useful as organocatalysts for the enantioselective Diels-Alder (DA) reaction between anthrone 10 and maleimide detivatives 11a-g. Enantioselectivity levels have been found to be dependent on several factors including nature of substituents in benzimidazole-triazoles 8a-g and 9a-g

A convenient methodology for the synthesis of substituted BINOL derivative using Cu-amine complexation method

534-537The oxidative coupling of substituted naphthol by Cu-amine complexation using Cu-Benzylamine has been achieved in excellent yield. This method offers a convenient and inexpensive route for the synthesis of substituted BINOL ligands

Design, synthesis, and characterization of novel BINOL-based heterocyclic analogues as potential sensors

<p>A new series of BINOL-based molecules have been synthesized. Their characterization has been performed by adequate spectroscopic techniques. Their chiral HPLC analyses have confirmed their chiral character. The compounds possess interesting flexible geometries and have structural features suitable for exhibiting host–guest interactions.</p

A convenient route to enantiomerically enriched furo-fused BINOL derivative

940-943A simple synthetic route has been developed to obtain a new axially chiral, C2-symmetric, modified BINOL with the introduction of methyl substituted furan ring fused to the BINOL 1 framework. The successful placement of the furan moiety at C-7; C-8 and C-7′; C-8′ positions of 1 resulted in the sterically demanding BINOL derivative. The synthesis of both enantiomers of methyl-substituted furo-fused BINOL has been carried out with high enantioselectivitie

A convenient route to benzimidazole fused chiral heterocyclic bases

707-712<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">An efficient synthetic protocol has been developed to obtain new chiral heterocyclic bases pyrrolo-benzimidazoles (DHP-Bz) and thiazolo-benzimidazoles (DHT-Bz). Notable characteristic of both series of the fused heterocycles is the presence of a chiral center. Chiral HPLC separations of the fused heterocycles have been achieved. These molecules possess structural features well-suited to function as chiral organocatalysts after resolution, apart from potential biological activities.</span

Chiral Heterocycle-Based Receptors for Enantioselective Recognition

The majority of biomolecules found in living beings are chiral, therefore chiral molecular recognition in living systems is crucial to life. Following Cram’s seminal work on the crown-based chiral recognition, prominent research groups have reported innumerable chiral receptors with distinctly different geometrical features and asymmetry elements. Main applications of such chiral receptors are found in chiral chromatography, as for analytical purposes and for bulk separation of racemates.Incorporation of heterocyclic rings in these recognition systems added a new dimension to the existing group of receptors. Heterocycles have additional features such as availability of unshared electron pairs, pronounced conformational features, introduction of hydrogen bonding and presence of permanent dipoles as well as specific spectral properties in certain cases. These features are found to enhance binding properties of the receptors and the selectivity factors between opposite enantiomers, allowing them to be effectively separated. The review presents the synthetic approaches towards these heterocyclic receptors and their distinctly different behavior vis-à-vis carbocyclic receptors

Tailor-Made Supramolecular Chirogenic System Based on <i>C</i>_<i>s</i>‑Symmetric Rigid Organophosphoric Acid Host and Amino Alcohols: Mechanistic Studies, Bulkiness Effect, and Chirality Sensing

A <i>C</i>_<i>s</i>-symmetric, rigid, achiral organophosphoric acid host with differentiable tautomeric structures has been developed for induced circular dichroism (ICD) studies of vicinal amino alcohols. The structural features of the host and the substituent bulkiness of the guest, together, decide the preferred mode of hydrogen binding on equilibration with a resultant ICD signal. An unequivocal rule correlating the absolute configuration of the guest amino alcohol with the ICD outcome is proposed