Here, we describe a general stereoselective synthesis of the marine furanosesquiterpenes structurally related to pallescensins 1–2. The stereoisomeric forms of the pallescensin 1, pallescensin 2, and dihydropallescensin 2 were obtained in high...
The cycloaddition of the chiral nitrile oxide 1 to 1-R-substituted 3,3-methylene-5,5-dimethyl-2-pyrrolidinones 2 (where R is H, n-butyl-, 1,1-dimethylethoxycarbonyl-, 1-methylethenyl- and acetyl-) proceeds regioselectively under the formation of spir...
Stereoselectivity is well known and very pronounced in drug metabolism and receptor binding. However, much less is known about stereoselectivity in drug membrane transport. Here, we characterized the stereoselective cell uptake of chiral phenylethyla...
Cycloaddition of C,N-diphenylnitrone to α-methylene-γ-butyrolactone afforded two diastereomeric 5-spirosubstituted isoxazolidines with high selectivity. Structural assignment was ascertained by NMR studies and an X-ray diffraction experiment on a sin...
New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino...
Strategic scaffolds in molecules increase the possibility of obtaining derivatives with potential uses in scientific and industrial areas. The regio- and stereoselective reactions can be considered to gain these tactical motifs. Natural diterpenes ar...
A reagent-controlled highly stereoselective reaction between (S)-difluoromethyl phenyl sulfoximine 1 and imines is reported, and this synthetic method provides a variety of enantiomerically enriched α-difluoromethyl amines. The main pros of thi...
Phase-transfer catalysis (PTC) is widely used in glycochemistry for the preparation of aryl glycosides by the glycosylation reaction. While investigating the possibility of synthesis of 4-(3-chloropropoxy)phenyl sialoside (Neu5Ac-OCPP) from N-acetyls...
We synthesized six new camphor-derived homochiral thioureas 1–6, from commercially available (1R)-(−)-camphorquinone. These new compounds 1–6 were evaluated as asymmetric organocatalysts in the stereoselective formation of glycosidi...
This review probes the recent developments in stereoselective reactions within the area of sulfoxonium ylide chemistry since the early 2000s. An abundance of research has been applied to sulfoxonium ylide chemistry since its emergence in the early 19...
Diosgeninlactone (1), a natural product from Solanum vespertilio, was stereoselectively synthesized in high yield from 3β-hydroxy-5-androstene.
The coupling of 2-bromo-3-benzoyloxycyclobutanone with purine under basic conditions produces two regioisomers consisting of the N-7 and N-9 alkylated products in equal amounts in their racemic forms. The distribution of the isomers is consistent wit...
Computational investigations on the bisphospholanoethane (BPE)-ligated Cu-catalyzed enantioselective addition of enynes to ketones were performed with the density functional theory (DFT) method. Two BPE-mesitylcopper (CuMes) catalysts, BPE-CuMes and...
(-)-Carvone (3) has been efficiently transformed into (-)-3β-hydroxycarvone (1), which is expected to be a useful synthon or chiral template in the synthesis of natural molecules. This short and efficient synthesis of compound 1 involves regioselecti...
The reactivity and stereoselectivity in the inverse-electron-demand Diels–Alder reaction between 4-methoxycarbonyl-N-(phenylsulfonyl)-1-aza-1,3-butadiene and methoxyethene was examined using density functional theory (DFT) calculations at the M...
The western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst) is a destructive defoliator of coniferous forests and a major cause of economic losses in forestry. A novel and efficient stereoselective synthesis of the sex pheromone of the western...
Treatment ofN-bromosuccinimide (NBS) with (carboethoxymethylene) triphenylphosphorane (1) in CH2Cl2 followed by the addition of an alcohol in the presence of manganese dioxide under ultrasonic irradiation constitutes a stereoselective one-pot procedu...
Bis-(o-dipheylphosphinophenyl)amine, a tridentate (PNP) chelating ligand, and several of their Rare Earth (RE) metal complexes, [bis-(o-dipheylphosphinophenyl)amido]-RER2, {[(C6H5)2P-o-(C6H4)]2NMR2 (R = -CH2-o-(C6H4)NMe2: M = Y, 1; Nd, 2; Gd, 3;), ar...
This review describes advances in the literature since the mid-1990s in the area of reactions of sulfonium ylide chemistry, with particular attention paid to stereoselective examples. Although the chemistry of sulfonium ylides was first popularized a...
An efficient and stereoselective catalytic system for the Heck cross coupling reaction using novel 1,3-dialkyl-3,4,5,6-tetrahydropyrimidinium salts (1, LHX) and Pd(OAc)2 loading has been reported. The palladium complexes derived from the salts 1a-f p...
Cobalt pi-complexes, previously described in the literature and specially synthesized and characterized in this work, were used as catalysts in homogeneous oxidation of organic compounds with peroxides. These complexes contain pi-butadienyl and pi-cy...
The novel Schiff base complex [CoIIIZnIIL3Cl2]·CH3OH (1) was synthesized by interaction of zinc powder, cobalt(II) chloride and methanol solution of the pre-formed HL in air (HL is the product of condensation of o-vanillin and methylamine) and...
The bimetallic compound Na[W2(μ-Cl)3Cl4(THF)2]·(THF)3 (1, {W 3 W}6+, a′2e′4) is a highly efficient room-temperature initiator for ring opening metathesis polymerization (ROMP) of norbornene (NBE) and some of its derivatives. In most cases, addition o...
The unexpected rearrangement of N-allyl-2-phenyl-4,5-dihydrooxazole-4-carboxamides in the presence of LiHMDS has been found. The key features are: (1) the net reaction consisted of 1,3-migration of the N-allyl group, (2) the rearrangement produced a...
The organic chemistry of ruthenium has been one of the most vigorously growing research areas over the past decades. Considerable effort has been extended towards the design and application of a broad series of ruthenium complexes, which culminated w...
A stereoselective synthesis of (6Z, 11Z)-octadecadienoic acid (1) and (6Z, 11Z)-eicosadienoic acid (2) from easily accessible pentane-1,5-diol (3) is described. Thus, compound 3 on pyranylation and oxidation gave the aldehyde 5 which was converted to...
Natural products obtained from marine organisms continue to be a rich source of novel structural architecture and of importance in drug discovery, medicine, and health. However, the success of such endeavors depends on the exact structural elucidatio...
This paper describes the development of a simple voltammetric biosensor for the stereoselective discrimination of myo-inositol (myo-Ins) and D-chiro-inositol (D-chiro-Ins) by means of bovine serum albumin (BSA) adsorption onto a multi-walled carbon n...
The stereo- and regioselective total syntheses of OMe derivatives of the scarce bioactive meroterpenoids makassaric acid (1) and fascioquinol B (2) have been accomplished. The synthetic sequences are based on the following three efficient and selecti...
Tolterodine (1) is a potent muscarinic receptor antagonist used in the treatment of overactive urinary bladder (OAB) syndrome. Tolterodine is chiral and it was patented, and is currently marketed, as the l-tartrate salt of the (R)-enantiomer. However...
Ginsenoside Rg3 (Rg3) has two epimers, 20(S)-ginsenoside Rg3 (SRg3) and 20(R)-ginsenoside Rg3 (RRg3), and while Rg3 itself has been reported to have anti-cancer properties, few studies have been reported on the anti-cancer effects of the different ep...
Propellanes are polycyclic compounds in which tricyclic systems share one carbon–carbon single bond. Propellane frameworks that consist of larger sized rings are found in a variety of natural products. As an approach to the stereoselective synt...
We have investigated the oxidative behaviour of natural compounds such as methyl abietate (1), farnesyl acetate (2), α-ionone (3), β-ionone (4), methyl linolelaidate (5), methyl linolenate (6) and bergamottin (7) with the oxidant system methyltrioxo-...
The enantioselective preparation of the two isomers of 4-hydroxy-2-cyclohexanone derivatives 1a,b was achieved, starting from a common cyclohexenone, through asymmetric transfer hydrogenation (ATH) reactions using bifunctional ruthenium catalysts. Fr...
The lithiation of 2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl diisopropylcarbamate (1) is achieved freely by sec-butyllithium in diethylether with high lk-diastereoselectivity: the bicyclic chelate complexes 3a and 3b are reacted with electrophiles to f...
Two approaches to the synthesis of para-menthene epoxide ((1S,5S,6R)-4) are developed. The first approach includes a reaction between chlorohydrin 7 and NaH in THF. The second involves the formation of epoxide in the reaction of corresponding diaceta...
The mechanism of the recently reported catalyzed asymmetric hydrogenation of enyne 1 catalyzed by the Co-(R,R)-QuinoxP* complex was studied by DFT. Conceivable pathways for the Co(I)-Co(III) mechanism were computed together with a Co(0)-Co(II) cataly...
Two new chiral, enantiomerically pure, hybrid P-N ligands, namely (2R,5S)-2-phenyl-3-(2-pyridyl)-1,3-diaza-2-phosphanicyclo[3,3,0]octan-4-one (1) and (2R,5S)-2-phenyl-3-(2-pyridyl)-1,3-diaza-2-phosphanicyclo[3,3,0]octane (2), have been synthesized st...
A series of iminopyridyl-based ligands, 6-[(Ar)N=C(R)]-2-C6H5N [(Ar = 2,6-Me2-C6H3, R = Me (L1); Ar = 2,6-iPr2-C6H3, R = Me (L2); Ar = 2,6-Me2-C6H3, R = H (L3); Ar = 2,6-iPr2-C6H3, R = H (L4); Ar = 3,5-(CF3)2-C6H3, R = Me (L5); Ar = C6F5, R = Me (L6)...
Hydrogen transfer reactions have exceptional importance, due to their applicability in numerous synthetic pathways, with academic as well as industrial relevance. The most important transformations are, e.g., reduction, ring-closing, stereoselective...
The main purpose of this work was to discover the way to obtain pure enantiomers of indan-1-ol. The subject of the study was the ability of the plant enzyme system to reduce the carbonyl group of indan-1-one, as well as to oxidize the hydroxyl group...
The stereoisomers (E)-2,2-dimethyl-4-(4-subsitutedstyryl)-2,3-dihydro-1H-[1,5]-benzodiazepine 3(a–d) were synthesized via the condensation reaction of 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepine (BZD) 1 with the benzaldehyde derivatives 2...
Biotransformations are reactions mediated by microorganisms, such as fungi. These bioreactions have high chemo- and stereoselectivity on organic substrates and can be applied in the search for new bioactive compounds. In this study, acanthoic acid (A...
The addition of interelement compounds with heteroatom-heteroatom single bonds to carbon-carbon unsaturated bonds under light irradiation is believed to be an atomically efficient method to procure materials with carbon-heteroatom bonds. In this stud...
The mechanism of the N-heterocyclic carbene (NHC)-catalyzed intramolecular Stetter reaction of salicylaldehyde 1 to yield chromanone 3 has been theoretically studied at the B3LYP/6-31G** level. This NHC-catalyzed reaction takes place through six elem...
Isoflavones are a class of natural products that exhibit a wide range of interesting biological properties, including antioxidant, hepatoprotective, antimicrobial, and anti-inflammatory activities. Scandenone (1), osajin (2), and 6,8-diprenylgenistei...
The total synthesis of (−)-antrocin and its enantiomer are presented. Antrocin (−)-1 is an important natural product which acts as an antiproliferative agent in a metastatic breast cancer cell line (IC50: 0.6 μM). The key features of t...
The thermoalkalophilic membrane-associated esterase E34Tt from Thermus thermophilus HB27 was cloned and expressed in Kluyveromyces lactis (KLEST-3S esterase). The recombinant enzyme was tested as a biocatalyst in aqueous and organic media. It display...
Two new copper(II) coordination compounds, namely a 1D coordination polymer [Cu(µ-cpna)(phen)(H2O)]n (1) and a discrete tetracopper(II) derivative [Cu(phen)2(H2O)]2[Cu2(µ-Hdppa)2(Hdppa)2] (2), were hydrothermally synthesized from copper(I...
The present study aimed to examine the stereoselective pharmacokinetics of racemic ketamine in dogs at low doses. The secondary aims were to identify associated behavioural effects and propose a ketamine infusion rate. The study was conducted on nine...
of 2