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Biocatalytic oxyfunctionalisation reactions are traditionally conducted in aqueous media limiting their production yield. Here we report the application of a peroxygenase in neat reaction conditions reaching product concentrations of up to 360 mM.

A modified macrocyclic glycopeptide-based chiral stationary phase (CSP), prepared via Edman degradation of vancomycin, was evaluated as a chiral selector for the first time. Its applicability was compared with other macrocyclic glycopeptide-based CSPs: TeicoShell and VancoShell. In addition, another modified macrocyclic glycopeptide-based CSP, NicoShell, was further examined. Initial evaluation was focused on the complementary behavior with these glycopeptides. A screening procedure was used based on previous work for the enantiomeric separation of 50 chiral compounds including amino acids, pesticides, stimulants, and a variety of pharmaceuticals. Fast and efficient chiral separations resulted by using superficially porous (core-shell) particle supports. Overall, the vancomycin Edman degradation product (EDP) resembled TeicoShell with high enantioselectivity for acidic compounds in the polar ionic mode. The simultaneous enantiomeric separation of 5 racemic profens using liquid chromatography-mass spectrometry with EDP was performed in approximately 3?minutes. Other highlights include simultaneous liquid chromatography separations of rac-amphetamine and rac-methamphetamine with VancoShell, rac-pseudoephedrine and rac-ephedrine with NicoShell, and rac-dichlorprop and rac-haloxyfop with TeicoShell.

Orthogonal protection and deprotection of amines remain important tools in synthetic design as well as in chemical biology and material research applications. A robust, highly efficient, and sustainable method for the formation of phenacyl-based carbamate esters was developed using CO2 for the in situ preparation of the intermediate carbamates. Our mild and broadly applicable protocol allows for the formation of phenacyl urethanes of anilines, primary amines, including amino acids, and secondary amines in high to excellent yields. Moreover, we demonstrate the utility by a mild and convenient photocatalytic deprotection protocol using visible light. A key feature of the [Ru(bpy)3](PF6)2-catalyzed method is the use of ascorbic acid as reductive quencher in a neutral, buffered, two-phase acetonitrile/water mixture, granting fast and highly selective deprotection for all presented examples.

In the last decade, manganese(II) complexes with N-donor tetradentate aminopyridine ligands emerged as efficient catalysts of enantioselective epoxidation of olefins and direct selective oxidation of C?H groups in complex organic molecules, with environmentally benign oxidant hydrogen peroxide. In this personal account, we summarize the progress of these catalysts with regard to ligands design, structure-reactivity correlations, evaluation of the substrate scope, as well as mechanistic studies, shedding light on the nature of active sites and the mechanisms of selective oxygenations. Several practically promising catalytic syntheses with the aid of Mn aminopyridine catalysts are exemplified.

Disclosed herein are polymorphic and amorphous forms of anhydrate, hydrate, and solvates of (R)-2-hydroxy-2-methyl-4-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dienyl)butanamide and methods of using such compositions for treating or suppressing oxidative stress disorders, including mitochondrial disorders, impaired energy processing disorders, neurodegenerative diseases and diseases of aging. Further disclosed are methods of making such polymorphic and amorphous forms.

2-Arylethylamine derivatives were synthesized using the Curtius reaction and with three different methods of preparing the acyl azide functional group. Carbamates derived from isocyanate were convenient protecting groups for alkylation of amines. Starting from benzaldehyde, amphetamine was prepared in three steps through an oxazolidin-2-one intermediate in 62% overall yield. Copyright Taylor & Francis Group, LLC.

Protocols for the stereodefined formation of α,α-disubstituted enolates of pseudoephedrine amides are presented followed by the implementation of these in diastereoselective alkylation reactions. Direct alkylation of α,α-disubstituted pseudoephedrine amide substrates is demonstrated to be both efficient and diastereoselective across a range of substrates, as exemplified by alkylation of the diastereomeric pseudoephedrine α-methylbutyramides, where both substrates are found to undergo stereospecific replacement of the α-C-H bond with α-C-alkyl, with retention of stereochemistry. This is shown to arise by sequential stereospecific enolization and alkylation reactions, with the alkyl halide attacking a common π-face of the E- and Z-enolates, proposed to be opposite the pseudoephedrine alkoxide side chain. Pseudoephedrine α-phenylbutyramides are found to undergo highly stereoselective but not stereospecific α-alkylation reactions, which evidence suggests is due to facile enolate isomerization. Also, we show that α,α-disubstituted pseudoephedrine amide enolates can be generated in a highly stereocontrolled fashion by conjugate addition of an alkyllithium reagent to the s-cis-conformer of an α-alkyl-α,β-unsaturated pseudoephedrine amide, providing α,α-disubstituted enolate substrates that undergo alkylation in the same sense as those formed by direct deprotonation. Methods are presented to transform the α-quaternary pseudoephedrine amide products into optically active carboxylic acids, ketones, primary alcohols, and aldehydes. Copyright

Novel lincomycin derivatives are disclosed. These lincomycin derivatives exhibit antibacterial activity. The compounds of the subject invention may exhibit potent activities against bacteria, including Gram positive organisms, and may be useful antimicrobial agents. Methods of synthesis and of use of the compounds are also disclosed.

(Chemical Equation Presented) The asymmetric propargylboration of aldehydes at -78°C in 98% ee). The reagents 1 are easily prepared in both enantiomeric forms with a simple Grignard procedure and air-stable borinate complexes 2. The ozonolysis of 6 proceeds smoothly through an acylsilane intermediate to give a TMS ester, which is hydrolyzed to the α-hydroxy acid quantitatively with water.

Reduction of N-t-BOC-protected-N-alkyl α-aminoketones with LiEt 3BH or Li(S-Bu)3BH furnishes protected syn-β-aminoalcohols with high selectivities. In contrast, removal of the BOC group followed by reduction of the aminoketone gives anti-β- aminoalcohols with variable selectivities. With aromatic ketones, selectivities are typically high while aliphatic ketones show mediocre to high selectivities depending on steric considerations.

The new imine derived from Myers (+)-pseudoephedrine glycinamide can be diastereoselectively alkylated with alkyl halides at room temperature using NaOEt or LiO-tert-Bu as bases under phase transfer conditions. Hydrolysis to the corresponding alkylated products was easily achieved under mild conditions to afford (R)-α-amino acids.

A very efficient method for performing stereoselective aldol reactions is reported. The reaction of (S,S)-(+)-pseudoephedrine-derived propionamide enolates with several aldehydes yielded exclusively one of the four possible diastereomers in good yields, although transmetalation of the firstly generated lithium enolate with a zirconium(II) salt, prior to the addition of the aldehyde, is necessary in order to achieve high syn selectivity. The so-formed syn-α-methyl-β-hydroxy amides were transformed into other valuable chiral nonracemic synthons such as α-methyl-β-hydroxyacids, esters, and ketones. Finally, a stereocontrolled reduction procedure starting from the so-obtained α-methyl-β-hydroxy ketones has been developed allowing the synthesis of either 1,3-syn- or 1,3-anti-α-methyl-1,3-diols in almost enantiopure form by choosing the appropriate reaction conditions.

The regio- and stereoselective synthesis of the protected cis-3- aminooxetanes cis-5 and cis-7 is reported. The oxetanes were obtained by the photocycloaddition of aliphatic (6c-e) and aromatic (4, 6a) aldehydes to the corresponding enamides (1a-d,h) or enecarbamates (1e-g). The enamine derivatives used in the Paterno-Buchi reaction were either commercially available or prepared from the corresponding acetaldehyde imines 2 by acylation. The oxetane formation proceeded with good-to-excellent simple diastereoselectivity for aromatic aldehydes (56-82% yield) and moderate selectivity for aliphatic aldehydes (46-55% yield). The cis-3-aminooxetanes are precursors for syn- and anti-1,2-amino alcohols. The relative configuration established in the photochemical step was retained upon nucleophilic ring opening between the oxygen atom and carbon atom C-4. By this means, syn-1,2-amino alcohols such as 8 and 10 were available in good yields. In contrast, the N-Boc-protected cis-3-aminooxetanes cis-5e and cis- 5f were transformed into anti-1,2-amino alcohols. Upon treatment with trifluoroacetic acid, they underwent an intramolecular nucleophilic substitution at the carbon atom C-2 of the oxetane and the oxazolidinones 11 and 12 were formed. Because the substitution occurs with inversion of configuration, anti-1,2-amino alcohols, e.g., ephedrine (15), are accessible.

We present the first cyanohydrin derivative 4 that allows diastereoselective umpolung reactions. In 4 the OH group of the cyanohydrin is linked with a chiral phosphate, which can be removed hydrolytically after asymmetric synthesis. Cyclization of pseudoephedrine 1d with POCl3 gave 2d. This was followed by addition of racemic benzaldehyde cyanohydrin 3 to give the key intermediate 4d. With complete retention of the configuration at phosphorus. Deprotonation of 4d, followed by addition of a wide variety of electrophiles afforded the crystalline products 5 with high diastereomeric excesses (de up to 94%). High asymmetric induction was also achieved for the reaction of 4-Li+ with acyl halides, α-bromoacetates, 2-cycloalkenones, α,β-unsaturated esters, and γ-bromoacetates. Lewis acid assisted hydrolysis proceeded without racemization and gave high yields of ketone cyanohydrins 6. From the ring-opened chiral auxiliary 7, optically pure pseudoephedrine 1 was readily recovered by acid hydrolysis. Optically pure (R) and (S) ketone cyanohydrins are now accessible in a very general strategy, which circumvents the substrate limitations of enzymatic synthesis.

N-t-Butyloxycarbonyl (Boc) substituted cis-2-phenyl-3-aminooxetanes 3 undergo a ring expansion to oxazolidinones 5 upon treatment with trifluoroacetic acid. The reaction occurs at the C(2) position under inversion of configuration. Alternatively, 3-aminooxetanes can be ring-opened at the less substituted C(4) position with retention of the relative configuration between C(2) and C(3) as exemplified by the synthesis of (+)-pseudoephedrine (2). The cis3-aminooxetanes serve as precursors for either syn- or anti-1,2-amino alcohols.

(1S,2S)-2-Amino-1-phenyl-1,3-propanediol (3a), a discarded optically active material in one of the processes for the manufacture of chloramphenicol, has been transformed into (S,S)-pseudoephedrine (4) and (R)-phenylalaninol (5). The opposite selectivity of highly regioselective oxidative ring opening of the benzaldehyde acetal of (1S,2S)-2-phthalimido-1-phenyl-1,3-propanediol by NBS and highly regioselective ring opening of the cyclic sulphite of the same substrate by LiBr are the key steps in the transformations respectively.

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The palladium-promoted deallylation of allylamines derived from primary and secondary amines is achieved with high to quantitative yield in the presence of 2-mercaptobenzoic acid as an allyl scavenger.This method was used for the sequential cleavage of diallylamines.A synthetic application of this procedure is presented in the preparation of secondary amines from diallylamines. - Keywords: allylamine; deallylation; sequential deprotection; ?-allyl palladium complexes; 2-mercaptobenzoic acid; substitution of amines

Allylcarboxy and Allyloxycarbonyl groups can be removed without affecting dimethylallylcarboxy and cinnamylcarboxy groups in the same molecule. using Pd(O) water soluble catalyst prepared in situ, with diethylamine as allyl scavenger. Homogeneous or biphasic media are suitable: the yields of deprotection are quantitative.

The reactivity of (-)-ephedrine (2) and (+)-norpseudoephedrine (3) towards the amid-acetals 1 a/b has been studied.Both 2 and 3 were acetylated resp. formylated at first at the amino group.Nevertheless, derivatives of 2 and 3 possessing a trisubstituted amino group react with 1 a in a sigmatropic rearrangement to ortho substituted dimethylcarbamoylmethyl derivatives.By subsequent reduction with lithiumaluminiumhydride the aromatic compounds 8, 13, and 18 with two aminoethyl groups are easily available.In contrast to these results 1 b did not furnish any rearrangement products. Keywords. (-)-Ephedrine; (+)-Norpseudoephedrine; N,N-Dimethylacetamid-dimethylacetal; N,N-Dimethylformamid-dimethylacetal; Sympathomimetic effects; Sigmatropic rearrangements.

The kinetics of protonation of pseudoephedrine by 3,6-di-tert-butyl-2-hydroxyphenoxyl have been analyzed by the ESR technique.It was shown that protolysis of the radical produced closed ionic pairs with the pseudoephedrine cation in a dimer state. Keywords: ESR, pseudoephedrine, 3,6-di-tert-butyl-2-hydroxyphenoxyl, ion pairs.

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Ephedrine and related optically active β-aminoalcohols can be prepared by zinc borohydride reduction of aryl O-protected magnesium imines and aryl α-hydroxyimimes which in turn are readily available from optically active cyanohydrins.

2-(2,5-Dimethylpyrrol-1-yl)alkanals, 2-(pyrrol-1-yl)alkanals, and 2-(2,5-dimethylpyrrol-1-yl)alkan-1-ones were prepared.The reactions of these compounds with Grignard and hydride reagents proceeded stereoselectively to give the corresponding 2-(pyrrol-1-yl)alcohols, which were converted into 2-aminoalcohols, such as norephedrine and ephedrine, by cleavage of the pyrrole ring.

A careafully coordinated study of the relations between structure and energetics of association in the crystalline state and solution is reported here.Hydrogen-bonded ion pairs formed from reaction between the enantiomers of mandelic acid, α-phenethylamine, ephedrine, and pseudoephedrine have been studied in dimethyl sulfoxide, dioxane, and water and as solid salts.Single-crystal X-ray analysis, performed on four unique diastereomeric pairs of (+/-)-ephedrinium and (+/-)-pseudoephedrinium (+/-)-mandelates yielded details of the solid-state hydrogen-bonding schemes for all eight diastereomeric salts. 1H NMR spectra (at 300 and 600 MHz) over a wide concentration range were determined and indicated a simple two-state equilibrium between ion pairs and free ions in dimethyl sulfoxide.The dissociation equilibria in dimethyl sulfoxide were examined more quantitatively by conductance and the results treated by the Fuoss-Justice, Fuoss-1977, and Onsager methods to yield calculated dissociation constants, equivalent conductances, and mean activity coefficients over a wide concentration range.Thermochemical properties determined by various techniques were (1) the heat of fusion by differential scanning calorimetry, (2) heats of solution of the crystalline salts to high dilution by isoperibolic batch calorimetry, and (3) heats of protonation and heats of dissociation from thermometric titration of solutions of mandelic acid with the bases.Extensive use was made of cross-chiral checks (e.g., R,R' vs S,S') to prove that observed chiral discrimination factors were real and accurate.Significant chiral discrimination factors were found for all properties of diastereomeric combinations.In several cases the largest differences in thermochemical properties and 1H NMR spectra of diastereomeric pairs could be related reasonably to differences in hydrogen-bonding schemes in their crystals.

Starting from the α-aminonitrile (1), the synthesis of (+) and (-)-threo-ephedrine, (6a) and (6b), has been achieved in overall yields of 20percent and 10percent, respectively, and in enantiomerically pure forms.

A new practical method for diastereoconversion of 2-amino alcohols was performed by treatment on N-Cbz- derivatives with trifluoromethanesulfonic anhydride or thionyl chloride, followed by ring cleavage of the resulting oxazolidin-2-ones

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The anodic oxidation of several different types of β-alkanolamines, R1R2C(OH)CR3R4NR5R6, was studied by cyclic voltammetry and controlled potential electrolysis in an aqueous carbonat buffer of pH 10 at a glassy carbon electrode.Upon oxidation, both the (α)C-(β)C and the C-N bonds are cleaved.Substituents R1-R4 affect the first oxidation potential and product distribution.The relative rates of the bond cleavages were estimated from the oxidation products.It was found that most of the amine cleaves through the (α)C-(β)C bond when at least one of the R groups is phenyl, nearly half cleaves through this bond when R is alkyl, and only about a tenth does so when R1-R4 are all hydrogen.The stability of the transient intermediates at the e-c step of the e-c-e process seems to affect the oxidation potentials and to govern the relative rates of the (α)C-(β)C bond cleavage.A scheme for the reaction processes is proposed.Keywords---β-alkanolamines; anodic oxidation; (α)C-(βC) bond fission; C-N bond fission; carbonate buffer; aldehyde; acetone; glycolaldehyde

α-N-Acylamino acids have been developed as useful reagents for the preparation of optically pure α-aminoalkylaryl ketones.Protection of the amino group as either the ethoxycarbonyl or benzenesulfonyl derivative allows alanine to serve as an effective educt for the chirally specific synthesis of a variety of structures containing the phenylethylamine backbone.Benzene undergoes Friedel-Crafts acylation with the N-acylalanine acid chloride.Catalyst complexation with oxagenated aromatics, however, prohibits acylation of aryl ethers.An arylmetallo reaction scheme overcomes this problem and also affords regiospecificity not attainable in conventional acylations.As examples, optically pure ephedrines and amphetamines were directly synthesized without recourse to resolution since the chirality of the amino acid educt was entirely conserved throughout the process.