A practical and enantioselective synthesis of tapentadol

FDA-approved drugs containing dimethylamine pharmacophore: a review of the last 50 years

Dimethylamine (DMA) derivatives represent a promising class of compounds with significant potential in the field of medicinal chemistry. DMA derivatives exhibit a diverse range of pharmacological activities, including antimicrobial, antihistaminic, anticancer, and analgesic properties. Their unique chemical structure allows for the modulation of various biological targets, making them valuable candidates for the treatment of numerous diseases. Synthetic strategies for the preparation of DMA derivatives vary depending on the desired biological activity and target molecule. Common synthetic routes involve the modification of the DMA scaffold through functional group manipulation, scaffold hopping, or combinatorial chemistry approaches. Therapeutically, DMA derivatives have shown promise in the treatment of infectious diseases, especially bacterial infections. Additionally, by focusing on particular biochemical pathways involved in tumor growth and metastasis, DMA-based drugs have shown anticancer activity. In addition to their direct pharmacological effects, DMA derivatives can serve as valuable tools in drug delivery systems, prodrug design, and molecular imaging techniques, enhancing their utility in medicinal chemistry research. Overall, DMA derivatives represent a versatile class of compounds with immense potential in medicinal chemistry. Further research and development efforts are warranted to explore their full therapeutic capabilities and optimize their clinical utility in the treatment of various diseases. This article outlines the pharmacological properties, synthetic strategies, and therapeutic applications of DMA derivatives of FDA approved drugs, highlighting their importance in drug discovery and development.

Enantioselective Intermolecular Murai-Type Alkene Hydroarylation Reactions

Strategies that enable the efficient assembly of complex building blocks from feedstock chemicals are of paramount importance to synthetic chemistry. Building upon the pioneering work of Murai and co-workers in 1993, C–H-activation-based enantioselective hydroarylations of alkenes offer a particularly promising framework for the step- and atom-economical installation of benzylic stereocenters. This short review presents recent intermolecular enantioselective Murai-type alkene hydroarylation methodologies and the mechanisms by which they proceed.

1 Introduction

2 Enantioselective Hydroarylation Reactions of Strained Bicyclic Alkenes

3 Enantioselective Hydroarylation Reactions of Electron-Rich Acyclic Alkenes

4 Enantioselective Hydroarylation Reactions of Electron-Poor Acyclic Alkenes

5 Enantioselective Hydroarylation Reactions of Minimally Polarized Acyclic Alkenes

6 Conclusion and Outlook

Diastereoselective and Enantioselective Conjunctive Cross-Coupling Enabled by Boron Ligand Design

Enantio- and diastereoselective conjunctive cross-coupling of β-substituted alkenylboron "ate" complexes is studied. Whereas β-substitution shifts the chemoselectivity of the catalytic reaction in favor of the Suzuki-Miyaura product, use of a boronic ester ligand derived from acenaphthoquinone allows the process to favor the conjunctive product, even with substituted substrates.

Tapentadol enantiomers: Synthesis, physico-chemical characterization and cyclodextrin interactions

The complete physico-chemical characterization of the single enantiomer analgesic drug R,R-tapentadol was quantitated in terms of protonation macro- and microconstants and octanol-water partition coefficient using pH-potentiometry, UV-pH and (1)H NMR-pH titrations. The protonation macroconstants were found to be logK1=10.59±0.01 and logK2=9.44±0.01, while the individual basicity of each protonation site was found to be logk(O)=9.94 and logk(N)=10.48 for the phenolate and tertiary amine functions, respectively. As a consequence, the zwitterionic form of tapentadol predominates in aqueous solutions. The potential optical impurity (S,S-tapentadol) was synthesized for the first time in a seven-step chiral synthetic procedure. The enantiomers of tapentadol were separated by cyclodextrin modified capillary zone electrophoresis. Over 15 cyclodextrins were investigated in terms of apparent complex stability and screened as chiral selectors, and the sulfated alpha-cyclodextrin was found to resolve the enantiomers with excellent resolution (Rs=16.2 and 9.1) at pH 4.75 and pH 9.0, respectively. The system containing 12mM selector in a 50mM TRIS-acetate buffer was amenable to detect S,S-tapentadol potential optical impurity at 0.1% concentration level.

Enantioselective Synthesis of Antiepileptic Agent, (−)-Levetiracetam, through Evans Asymmetric Strategy

A practical and efficient enantioselective synthesis of antiepileptic drug, (−)-Levetiracetam, has been described in five steps (33.0% overall yield) and high optical purity (99.0%ee), using Evans asymmetric strategy forα-alkylation of carbonyl functionality as the key step. The simplicity of the experimental procedures and high stereochemical outcome make this method synthetically attractive for preparing the target compound on multigram scales.