o-Iodoxy Benzoic Acid–Mediated Synthesis of 3,5-Diarylisoxazoles and Isoxazole-3-carboxylic Acids

A new, convenient, ecofriendly synthesis of 3,5-diarylisoxazoles is reported from α,β-unsaturated ketoximes. Similarly, a novel synthesis of isoxazole carboxylic acids is also reported. Both the methods use efficient, environmentally friendly, and nontoxic iodoxybenzoic acid (IBX) as an oxidative cyclizing reagent. Easy procedure, environmentally benign reaction conditions, and nontoxicity are advantages to the methodology.     

On the type II error in SIMCA method

A novel method for theoretical calculation of the type II (β) error in soft independent modeling by class analogy is proposed. It can be used to compare tentatively predicted and empirically observed results of classification. Such an approach can better characterize model quality and thus improve its validation. Method efficiency is demonstrated on the famous Fisher Iris dataset and on a real‐world example of quality control of packed raw materials in pharmaceutical industry. Copyright © 2014 John Wiley & Sons, Ltd.     

A concise enantioselective synthesis of l-(−)-733,061 and (2S,3S)-methyl 3-aminopiperidine-2-carboxylate using catalytic enantioselective aza-Henry reaction as key step

An efficient enantioselective synthesis of l-(−)-733,061 and (2S,3S)-methyl 3-aminopiperidine-2-carboxylate is accomplished by means of catalytic enantioselective aza-Henry reaction. A key feature of this protocol is organocatalysis as genesis of chirality to ensure high degree of distereo- and enantiocontrol.     

Synthesis of new fluorescently labeled glycosylphosphatidylinositol (GPI) anchors

The borondipyrromethene (BODIPY) labeled new glycosylphosphatidylinositol (GPI) molecules were synthesized as cellular probes to study the chemical basis of microdomain organization of GPI-anchored proteins and cholesterol in plasma membrane. The synthesis enabled by a new stereo-selective glycosylation of myo-d-inositol acceptor led to the preparation of optically pure glucosaminyl-(1-6)-α-phosphatidyl-myo-d-inositol and its unnatural stereoisomer.     

Design and synthesis of boron containing 2,4-disubstituted-phthalazin-1(2H)-one and 3,7-disubstituted-2H-benzo[b][1,4] oxazine derivatives as potential HGF-mimetic agents

We synthesized boron containing 2-(4-methoxybenzyl)-4-(4-(4,4,5,5-tetramethyl-1,3,2-dioaborolan-2-yl)phenyl) phthalazin-1(2H)-one 3 and 7-methyl-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-2H-benzo[b][1,4] oxazine 8. The reaction of compound 2 with B₂pin₂ using potassium acetate as the base and Pd(PPh₃)₂Cl₂ as the catalyst, produced the corresponding boron-containing derivative 3 as a white solid in 65% yield. Alternatively, we have synthesized compound 8 as a yellow solid in 59% yield using the Miyaura borylation reaction. The potassium trifluoro(4-(-methyl-2H-benzo[b][1,4]oxazine-3-yl)phenylborate 9 was then obtained after treatment of 8 with aqueous solution of KF₂H in methanol as white solid product in 60% yield. The biological activities of the synthetic compounds are currently being evaluated.     

Unusual mechanistic pathway for the synthesis of novel spiro-oxindoles via 3-phenyl-5-isoxazolone ring cleavage by secondary amino acids

A new approach to synthesize a series of spiro-oxindole derivatives via a multicomponent reaction of isatin, 3-phenyl-5-isoxazolone, and sarcosine or l-proline which play a dual role of base and nucleophile in methanol under reflux condition is reported. Also spiroindan-1,3-diones were synthesized from ninhydrin and 3-phenyl-5-isoxazolone. The methodology affords high yields of products in a short reaction time.     

A novel approach for the one-pot synthesis of linear and angular fused quinazolinones

A convenient and inexpensive one step methodology has been developed for the synthesis of linear and angular fused quinazolinones. The protocol, which uses amino heterocycles and o-bromo benzyl/naphthyl bromides as reactants, CuI as catalyst, Cs₂CO₃ as base, l-proline as ligand, and DMF as solvent, proceeds via nucleophilic aromatic substitution of the N-heteroaromatic cationic intermediate followed by in situ aerial oxidation at the benzylic position to the quinazolinone scaffold.     

Enantioselective addition of phenylacetylene to aldehydes catalyzed by a d-glucosamine-derived sulfonamide-titanium complex

We present the synthesis of β-hydroxy sulfonamides derived from d-glucosamine and their application as ligands in titanium tetraisopropoxide promoted enantioselective addition of phenylacetylene to benzaldehyde and selected aromatic and aliphatic aldehydes. The N-3,5-bis(trifluoromethyl)benzenesulfonamido-d-glucosamine derivative was chosen as the most efficient ligand for this addition. The reaction is highly enantioselective for several aromatic aldehydes and enantiomeric excesses up to 92% were obtained.     

A bioinspired look at the glucosinolate metabolic pathway. Structural insights into the reaction of benzyl isothiocyanate and d-glucosamine

Through a well-established enzymatic transformation glucosinolates release reactive isothiocyanates that can undergo further metabolic pathways affording a plethora of reactive metabolites. This study explores in detail the reaction of benzyl isothiocyanate, which possesses antitumor activity as alkylating agent, with d-glucosamine, commonly employed in oral treatments against osteoarthritis and inflammation. Structures of the resulting products and their evolution have been assessed and compared with those involving d-glucose, reported previously. Chemical results suggest that clinical treatments with d-glucosamine could reduce the beneficial effects associated with diets based on glucosinolate-rich foods.     

An efficient and novel synthesis of chromonyl chalcones using recyclable Zn(l-proline)2 catalyst in water

A novel approach was adopted for the synthesis of a series of chromonyl chalcones (3a-o) from 3-formylchromones (1a-c) and different cyclic active methyl compounds (2a-e), employing Zn(l-proline)₂ as a recyclable Lewis acid catalyst in water. In each conversion, the catalyst was successfully recovered and reused several times without significant loss in yield and selectivity. All the newly synthesized compounds were characterized using elemental analysis and spectral data (IR, ¹H NMR, ¹³C NMR and mass spectrometry).