An enantiodivergent and formal synthesis of paroxetine enantiomers by asymmetric desymmetrization of 3-(4-fluorophenyl)glutaric anhydride with a chiral SuperQuat oxazolidin-2-one

Expanding the Role of Chiral Drugs and Chiral Nanomaterials as a Potential Therapeutic Tool

Chirality, the property of molecules having mirror-image forms, plays a crucial role in pharmaceutical and biomedical research. This review highlights its growing importance, emphasizing how chiral drugs and nanomaterials impact drug effectiveness, safety, and diagnostics. Chiral molecules serve as precise diagnostic tools, aiding in accurate disease detection through unique biomolecule interactions. The article extensively covers chiral drug applications in treating cardiovascular diseases, CNS disorders, local anesthesia, anti-inflammatories, antimicrobials, and anticancer drugs. Additionally, it explores the emerging field of chiral nanomaterials, highlighting their suitability for biomedical applications in diagnostics and therapeutics, enhancing medical treatments.

Recent Advances in the Synthesis of the Antidepressant Paroxetine

Paroxetine is a potent inhibitor of serotonin reuptake and is widely prescribed for the treatment of depression and other neurological disorders. The synthesis of paroxetine and the possibility to prepare derivatives with a specific substitution pattern that may allow their use as biological probes is an attractive topic especially for medicinal chemists engaged in neurosciences research. Considering the extensive work that was developed in the last decade on the total synthesis of paroxetine, this review summarizes the most important contributions in this field, organized according to the reagent that was used as a starting material. Most of the methods allowed to prepare paroxetine in 4-9 steps with an overall yield of 9-66%. Despite the progress made in this area, there is still room for improvement, searching for new eco-friendly and sustainable synthetic alternatives.

Enantiopure 4-oxazolin-2-ones and 4-methylene-2-oxazolidinones as chiral building blocks in a divergent asymmetric synthesis of heterocycles

Enantiopure 3-((R)- and 3-((S)-1-phenylethyl)-4-oxazoline-2-ones were evaluated as chiral building blocks for the divergent construction of heterocycles with stereogenic quaternary centers. The N-(R)- or N-(S)-1-phenylethyl group of these compounds proved to be an efficient chiral auxiliary for the asymmetric induction of the 4- and 5-positions of the 4-oxazolin-2-one ring through thermal and MW-promoted nucleophilic conjugated addition to Michael acceptors and alkyl halides. The resulting adducts were transformed via a cascade process into fused six-membered carbo- and heterocycles. The structure of the reaction products depended on the electrophiles and reaction conditions used. Alternative isomeric 4-methylene-2-oxazolidinones served as chiral precursors for a versatile and divergent approach to highly substituted cyclic carbamates. DFT quantum calculations showed that the formation of bicyclic pyranyl compounds was generated by a diastereoselective concerted hetero-Diels-Alder cycloaddition.

Catalytic Michael/Ring-Closure Reaction of α,β-Unsaturated Pyrazoleamides with Amidomalonates: Asymmetric Synthesis of (-)-Paroxetine

A highly enantioselective tandem Michael/ring-closure reaction of α,β-unsaturated pyrazoleamides and amidomalonates has been accomplished in the presence of a chiral N,N'-dioxide-Yb(OTf)₃ complex (Tf: trifluoromethanesulfonyl) to give various substituted chiral glutarimides with high yields and diastereo- and enantioselectivities. Moreover, this methodology could be used for gram-scale manipulation and was successfully applied to the synthesis of (-)-paroxetine. Further nonlinear and HRMS studies revealed that the real catalytically active species was a monomeric L-PMe₂ -Yb³⁺ complex. A plausible transition state was proposed to explain the origin of the asymmetric induction.

Synthesis of chiral lactams via asymmetric hydrogenation of α,β-unsaturated nitriles

A highly efficient Rh-catalyzed asymmetric hydrogenation of α,β-unsaturated nitriles containing ester/amide groups is reported affording chiral nitriles with excellent enantioselectivities (up to 99.7% ee) and high activity (TON up to 10 000).

Total Synthesis of (±)-Paroxetine by Diastereoconvergent Cobalt-Catalysed Arylation

A total synthesis of paroxetine is reported, with a diastereoselective and diastereoconvergent cobalt-catalysed sp3-sp2 coupling reaction involving a 3-substituted 4-bromo-N-Boc-piperidine (Boc = tert-butoxycarbonyl) substrate as a key step. A 9:1 diastereoselectivity was obtained, while a control experiment involving a conformationally locked 3-substituted 4-bromo-tert-butyl cyclohexane ring proceeded with essentially complete stereoselectivity.