Design and synthesis of α-aminonitrile-functionalized novel retinoids

The vital use of isocyanide-based multicomponent reactions (MCR) in chemical synthesis

Multicomponent (MCRs) reactions are classified as one-pot reaction where more than two starting materials are employed to form a single product that contains the building blocks of the starting components. MCRs are considered a convenient approach in synthetic chemistry and have many advantages over the traditional one or two-component reaction, by reducing the number of sequential multiple steps required and often producing better yields. This chapter dissects the use of isocyanide-based MCRs and the elegant chemistry that they offer to build useful scaffolds in the chemical synthetic field. In addition MCRs are considered as one of the recognisable options for increasing “greenness” during the synthesis of pharmaceutical and industrial products.

Nanostructured oxytyramine catalyst for the facile one-pot synthesis of cyclohexanecarbonitrile derivatives

A magnetic, recyclable heterogeneous organocatalyst, OT@Si@SPIONs, has been developed for the facile synthesis of cyclohexanecarbonitriles.

Catalytic Synthesis of α-Aminonitriles Using Nano Copper Ferrite CuFe2O4 under Green Conditions

Copper ferrite nanomaterial CuFe2O4 as reusable heterogeneous initiator in the synthesis of α-aminonitriles. The nanocatalyst is easily recovered and its reusability is recorded. Synthesis of α-aminonitriles derivatives by one-pot reaction of different aldehydes with amines and trimethylsilyl cyanides has been developed using nano copper ferrite CuFe2O4 catalyst under room temperature and green solvent (water as solvent) conditions. α-aminonitriles are important in preparing a wide variety of amino acids, amides, diamines, and nitrogen containing heterocycles.

Chemical modulation of chaperone-mediated autophagy by retinoic acid derivatives

Chaperone-mediated autophagy (CMA) contributes to cellular quality control and the cellular response to stress through the selective degradation of cytosolic proteins in lysosomes. Decrease in CMA activity occurs in aging and in age-related disorders (for example, neurodegenerative diseases and diabetes). Although prevention of this age-dependent decline through genetic manipulation in mouse has proven beneficial, chemical modulation of CMA is not currently possible, due in part to the lack of information on the signaling mechanisms that modulate this pathway. In this work, we report that signaling through the retinoic acid receptor alpha (RARα) inhibits CMA and apply structure-based chemical design to develop synthetic derivatives of all-trans-retinoic acid (ATRA) to specifically neutralize this inhibitory effect. We demonstrate that chemical enhancement of CMA protects cells from oxidative stress and from proteotoxicity, supporting a potential therapeutic opportunity when reduced CMA contributes to cellular dysfunction and disease.

Design and synthesis of boron containing potential pan-RAR inverse agonists

We designed and successfully synthesized the compounds 5 and 8 as potential pan-RAR (retinoic acid receptor) agonists. These two compounds were designed based on an existing pan-RAR agonist (BMS493). We synthesized compound 5, in which the carboxylic acid group in BMS 493 was replaced by boronic ester; and compound 8, in which the double bond of BMS 493 was changed to an oxadiazole (as bioisosteres of double bond) ring. The two target molecules 5 and 8 were synthesized from the commercially available 7-bromo-4,4-dimethyl-3,4-dihydronaphthalen-1(2H)-one 1. Compound 1 was derivatized to intermediate 5,5-dimethyl-8-(phenylethynyl)-5,6-dihydronaphthalene-2 carbaldehyde 4 by using alkylation, dehydration, and metal exchange reactions. The intermediate 4 was further converted to 5 by using a Wittig reaction and to 8 by amide coupling and dehydration to give overall 18% and 33% yields, respectively, after 8 steps in each case.

A truly green synthesis of α-aminonitriles via Strecker reaction

Background

The classical Strecker reaction is one of the simplest and most economical methods for the synthesis of racemic α-aminonitriles (precursor of α-amino acids) and pharmacologically useful compounds.

Results

Indium powder in water is shown to act as a very efficient catalyst for one-pot, three-component synthesis of α-aminonitriles from diverse amines, aldehydes and TMSCN. This general rapid method is applicable to a wide range of amines and aldehydes and produces products in excellent yield.

Conclusions

The present one-pot, three-component environmentally benign procedure for the synthesis of α-aminonitriles will find application in the synthesis of complex biologically active molecules.

Design and Synthesis of 3,5-Disubstituted 1,2,4-Oxadiazole Containing Retinoids from a Retinoic Acid Receptor Agonist

We previously synthesized novel retinoid libraries, and after screening for bioactivity found one compound BT10 that functions as a specific agonist for retinoic acid receptors. This lead compound was further derivatized using SAR and LRD to obtain 3,5-disubstituted-1,2,4-oxadiazole-containing retinoids. The new oxadiazole (amide bioisosters)-containing retinoids (compounds 1, 2, 3, 4, 5, and 6) were synthesized in 42-65% yield by reacting with (E)-4-((3-ethyl,2-4,4,4-trimethylcyclohex-2-enylidene)methyl)benzoic acid and phenyl substituted amidoxime in DMF using CDI as the coupling reagent. The biological activities of the synthesized compounds are currently being evaluated.