Short and practical enantioselective synthesis of linezolid and eperezolid via proline-catalyzed asymmetric α-aminooxylation

Facile Synthesis of Oxazolidinones as Potential Antibacterial Agents

An efficient microwave-assisted synthesis route for novel oxazolidinone analogues has been developed. The general synthesis of these compounds began with an L-proline-mediated three-component Mannich reaction between commercially available 3-fluoro-4-morpholinoaniline, aqueous formaldehyde and α-hydroxyacetone. This was followed by a one-step cyclisation to form the core structure of oxazolidinone antibiotics which was subsequently derivatized. The novel compounds were evaluated for their antibacterial activity against M. smegmatis. One of the novel oxazolidinone derivatives 18 a1 produced a MIC of 8 mg/L, comparable with the commercial Rifampicin. The methodology is a useful addition to the field since it can make highly sought-after oxazolidinone derivatives, using cheaper, less harsh commercially available reagents, in a short time and one pot.

Strategies towards the synthesis of anti-tuberculosis drugs

In this report, we reviewed the strategies towards the synthesis of anti-tuberculosis drugs. They include semisynthetic approaches, resolution based strategies, microbial transformations, solid phase synthesis, and asymmetric synthesis.

Organocatalyzed asymmetric alpha-oxidation, alpha-aminoxylation and alpha-amination of carbonyl compounds

Organocatalytic asymmetric α-oxidation and amination reactions of carbonyl compounds are highly useful synthetic methodologies, especially in generating chiral building blocks that previously have not been easily accessible by traditional methods. The concept is relatively new and therefore the list of new catalysts, oxidizing and aminating reagents, as well as new substrates, are expanding at an amazing rate. The scope of this review includes new reactions and catalysts, mechanistic aspects and synthetic applications of α-oxidation, hydroxylation, aminoxylation, amination, hydrazination, hydroxyamination and related α-heteroatom functionalization of aldehydes, ketones and related active methylene compounds published during 2005–2009.

Regioselective and stereospecific synthesis of enantiopure 1,3-oxazolidin-2-ones by intramolecular ring opening of 2-(Boc-aminomethyl)aziridines. Preparation of the antibiotic linezolid

The amide moiety of several enantiopure unactivated 1-aryl- or 1-alkylaziridine-2-carboxamides were reduced and then N-Boc-protected to afford enantiopure 2-(Boc-aminomethyl)aziridines, which were further converted into enantiopure 5-(aminomethyl)-1,3-oxazolidin-2-ones by means of a stereospecific and fully regioselective BF3.Et2O-promoted intramolecular nucleophilic ring opening. One of these oxazolidinones was transformed into the antibiotic linezolid through a CuI-catalyzed N-arylation reaction at its carbamate moiety.

Organocatalytic Sequential α-Amination−Horner−Wadsworth−Emmons Olefination of Aldehydes: Enantioselective Synthesis of γ-Amino-α,β-Unsaturated Esters

A novel and highly enantioselective method for the synthesis of gamma-amino-alpha,beta-unsaturated esters via tandem alpha-amination-Horner-Wadsworth-Emmons (HWE) olefination of aldehydes is described. The one-pot assembly has been demonstrated for the construction of functionalized chiral 2-pyrrolidones, subunits present in several alkaloids. [structure: see text]