The reactions of N,N -substituted enaminones with TEMPO leading to the synthesis of 2,2-dimethyl pyrrolidine functionalized new enaminones have been established by Ni(II) catalysis. Interesting ring contraction on TEMPO as well as the enaminone C-N bond amination bring new tool for generating molecular diversity of enaminones in the amino group fragment.

We have quantum chemically studied the palladium-mediated activation of C(spn)–X bonds (n = 1–3; X = F, Cl, Br, I) in the archetypal model substrates H3C–CH2–X, H2C=CH–X, and HC≡C–X by a model bare palladium catalyst, using relativistic density functional theory at ZORA-BLYP/TZ2P. The bond activation reaction barrier decreases, for all sp-hybridized carbon centers, when the substituent X of the substrate

Metallaphotoredox catalysis represents the combination of two activation modes, viz; metal-catalyzed C-H functionalization and visible-light-induced photocatalysis. This appealing dual catalysis technique has evolved as a versatile platform that has paved the way for diverse low-energy pathways for a plethora of synthetic transformations. The synergistic combination of two “green” approaches has garnered

1-Methylthio-2-arylethynes were prepared in typically good to excellent yields from aryl iodides and 1-methylthio-2-(trimethylsilyl)-ethyne by a desilylative Sonogashira process employing Pd(PPh 3 ) 2 Cl 2 (1 mol%), CuI (10 mol%), and K 2 CO 3 (6 eq) in MeOH-Et 3 N-THF (1:2:2) at rt for 16 h (16 examples, 31-96% yield). Thienyl and pyridyl iodides (all regioisomers) were similarly converted to 1-m

Sulfonyl fluorides have found diverse applications in multiple disciplines due to their reactivity and stability. Thus, exploiting the new reactivity of sulfonyl fluorides is of high importance to Sulfur (VI) Fluoride Exchange (SuFEx) chemistry. Reported herein is a three-component reaction of β-keto sulfonyl fluorides, arynes and DMF for the streamline synthesis of sulfocoumarins. The reaction proceeds

Thiiranes, the corresponding sulfur analogues of epoxides, are less studied and less encountered in literature. This might be due to the limited existing synthetic approaches for their synthesis. Herein, a mild, sustainable and efficient organocatalytic synthesis of thiiranes has been developed. Starting from olefins and utilizing the epoxidation protocol developed in the Kokotos’ group, which employs

A novel electrochemical synthesis of azaborininones was developed using 2-aminobenzamide and boronic acid as the reagents under mild conditions. The great advantage of this reaction system is avoiding using metal catalysts and high-temperature. Various 1,3,2-benzodiazaborininones were obtained in moderate to excellent yields.

N -heterocyclic carbene (NHC) catalysis has become a versatile catalysis strategy for building molecules via unique reaction modes. Dual catalytic processes using NHCs in combination with additional modulating agents such as another organocatalyst or transition-metal catalyst have also been studied. The clear selection of cocatalysts has led to enhanced reactivity, increased yields, and/or improved

In this study, we have developed efficient strategies for the synthesis of glycosyl donors with 2-thioacetyl (SAc) groups in order to synthesize 2-deoxysugars with absolute α/β-configuration. Starting from free methyl glycosides, four methyl 2-SAc glycosides were synthesized with high efficiency mainly through the double serial inversion strategy, and further turned into four corresponding 1-OAc, 2-SAc

2-Nitroglycal is a widely used synthon for aminoglycosides synthesis. Herein, we report an efficient method for 2-nitroglycals synthesis using n Bu 4 NNO 3 /Tf 2 O/DTBMP. Using 3-O-acetyl-2-nitroglycals as donors, a novel method for the construction of challenging 1,2-cis-2,3-diamino-2,3-dideoxyglycosidic linkages was established using 4-pyrrolidinopyridine (PPY) mediated relay glycosylation reaction

Imidazoles constitute an important class of heterocyclic compounds with extensive potential use, from pharmaceuticals to optoelectronics. However, synthetic methodologies capable of producing novel nonsymmetric imidazoles are still scarce. In a combined synthesis, photophysical and computational investigation, we show that ruthenium(II) catalysis enables C–H/N–H alkyne annulation of nonsymmetric imidazoles

Ethyl diazoacetate (EDA), which is easily prepared from ethyl glycinate and NaNO 2 , reacts in situ with alkynes in a water micelle environment without organic solvent to form pyrazoles. The reaction is pH dependent, as in the presence of protic catalysis (H 2 SO 4 4%, pH 3.5) a mixture of 3,5- and 4,5-disubstituted pyrazoles was obtained, while, at pH 5.5, only the 3,4-disubstituted isomer was obtained

A vast variety of oxidation procedures is known to obtain 2,2,6,6-tetramethylpiperidinyl-4-oxyl (TEMPO) moieties from its piperidinyl precursor. However, up to now no comprehensive study has been performed concerning the performance and feasibility for lab-scale synthesis. With the focus on the ease of synthesis, occurring impurities, the reaction yield and the degree of oxidation (DoO), this study

The Friedel-Crafts sulfonylation for the synthesis of diaryl sulfones derivatives was achieved by using triflic acid (TfOH) as the acidic catalyst with arylsulfonyl chlorides and arenes at elevated temperatures. Different sulfones could be synthesized with this method in good to excellent yield and with high selectivity. In contrast to the previous methodology reported for this sulfonylation, the catalyst

In these two decades, Diversity-Oriented Synthesis (DOS) has changed significantly: from the historical focus on structural diversity, new approaches have been developed in order to increase the biological outcome of the molecules within the library, such as the privileged-based DOS or the Diversity-Oriented Fluorescence Library Approach (DOFLA). In this context, chemoinformatics can assist organic

The fraction of sp 3 -hybdrised carbons (Fsp 3 ) in drug candidates and other biologically relevant compounds has been proposed to be an important physicochemical consideration within medicinal chemistry. Currently available small-molecule probes for Raman imaging are not optimised for biological applications. We sought to improve upon the highly Raman-active, yet rigid, lipophilic, and aggregative

A set of Steroidal Molecular Rotors (SMRs) was synthesized and characterized employing a Sonogashira cross-coupling reaction as the key synthetic step. The static dipole moment ( μ 0 ) of the stator was examined as a crystal engineering criterium that could determine the easiness with which the rotator participates in the high energy supramolecular interactions that frequently preclude rotation in

The tristriazolotriazine (TTT) N -heterocycle, despite being a relatively new mesogenic core for use in discotic liquid crystals, has already demonstrated its importance and promising characteristics. In this work, we extended the knowledge about the TTT, increasing the core size with alkoxybenzoate units, as well as evaluating how the expansion and number of peripheral chains affected the thermal

This study reports on the one-step, green, catalyst-free synthesis of new naphthoquinone-polyphenols through an innovative method using the multicomponent domino Mannich-Michael reaction in the lawsone. After optimized condition reactions, twelve novel naphthoquinone polyphenols were synthesized with good yields. The polyphenols were tested on four cancer cell lines (HCT116, PC3, HL60, and SNB19),

Recently, novel C5-position unprotected mesoionic N-heterocyclic olefins (mNHOs) demonstrated interesting reactivity with various Lewis acids in experiment. In this work, extensive DFT calculations show that the isomerization of such mNHOs to more Lewis-basic mesoionic carbenes (MICs) can be efficiently catalyzed by weakly protic acidic species including C5-unprotected mNHOs, their Lewis adducts and

Herein, we describe the N -iodosuccinimide-mediated benzyl sp 3 C–H oxidation of 2-alkyl-substituted benzamide derivatives. This Hofmann-Löffler-Freytag (HLF) type reaction involving intramolecular sp 3 C–O bond formation differs from the construction of the C–N bond in the classic and modified HLF reactions. This reaction proceeded smoothly via 1,5-hydrogen atom transfer of N-centered radicals directly

Sulfoxonium ylides in recent years have proved to be versatile building blocks and have found applications towards the synthesis of structurally diverse organic molecules. In this research article, we delineate a new oxidative, molecular iodine-mediated transformation on sterically encumbered arylated sulfoxonium ylides, that give access to 1,2-dicarbonyl containing compounds. Twenty-six examples have

Selective modification of carbohydrate residues in glycopeptides is highly relevant as a tool in glycobiology. Oxidation in particular allows subsequent ligation with a label or handle and can be effectuated enzymatically or chemically. Chemical oxidation of carbohydrate residues in glycopeptides is nearly invariably done using periodate cleavage, leading to aldehydes. In this work we apply palladium-catalyzed

Structurally complex cedrane scaffolds were synthesized in a very good yields with high chemo- and diastereoselectivities in a sequential one-pot manner by using a combination of intermolecular olefination, intramolecular Michael and Michael reactions or intermolecular olefination, intramolecular Michael and aldol reactions as the key steps from the readily available hydroxy- p -quinone butanals and

Cyclization strategies employing imides and their derivatives have attracted the attention of several organic chemists interested in synthesizing polycyclic alkaloids. Numerous strategies have been developed, mostly focused on i) the use of masked iminium ions, ii) addition of weak nucleophiles onto the carbonyl group of the imide being activated by a Lewis or Brønsted acid, iii) addition of strong

Amino acid decorated imidazole, pyrimidine and purine derivatives, resembling analogues of peptide nucleic acid’s building blocks, have been synthesized by a three-way multicomponent chemistry of diaminomaleonitrile, one of the most studied chemical precursors in prebiotic chemistry. The regioselectivity of the multicomponent reaction between diaminomaleonitrile, trimethyl orthoacetate and a selected

Chiral isoxazole and carbocyclic pyrimidine nucleoside analogues were synthesized via (3+2)-cycloadditions of chiral pyrimidinyl-substituted dimethyl cyclopropanedicarboxylates. In the presence of MgI 2 , (3+2)-cycloadditions of chiral pyrimidinyl-substituted cyclopropanes with nitrosoarenes afforded diverse chiral isoxazole pyrimidine nucleoside analogues in up to 78% yield and 88-96% ee. Using Nd(OTf)

A concave indolo[3,2,1- jk ]carbazole-based compound was synthesized and characterized, which was further compared with the property of its planar congener. The results reveal that the change in molecular shape alters the molecular electronic structure, thus leading to the reduced aromaticity and divergent energy levels of frontier molecular orbitals of the concave compound. Moreover, the bowl-shaped

Synthetic investigation to achieve a novel intermediate of tamiflu by using cis -aziridine as a chiral building block which is readily synthesized from ᴅ-mannitol as a renewable starting material has been presented. The present approach utilizes the intramolecular Horner-Wadsworth-Emmons reaction as the key step for the synthesis of tamiflu. On the other hand, diene containing allylic aziridine framework

The combination of a biocatalytic asymmetric C=C reduction with a simple sequence of chemical transformations was implemented in a new chemoenzymatic synthesis of various substituted aryloxyalkanoic acids, used as weed-killing agrochemicals or chiral precursors. By careful selection of the biocatalyst, either enantiomer of the product could be obtained in good yield and moderate to good ee. The method

Tandem C, H-arylation and C,H-amidation of cis -cinnamyl hydroxamates using a single metal catalyst (and air as oxidant) leads to the formation of 3-aryl-2-quinolone ring system in a regioselective manner. The corresponding trans-isomer under identical conditions gives rise to 4-aryl-2-quinolone derivative. The complementary regioselectivity observed during tandem C,H-arylation C,H-amidation of isomeric

A straightforward synthesis of a highly substituted biomass-derived chiral pyrrolidine conveniently functionalized to obtain macrocycles through intramolecular “click” reactions is reported. The experimental difficulties encountered during the macrocyclization stage led us to conduct an extensive DFT study to understand the origins of the findings. The results obtained suggest that the improper conformational

The convenient synthesis of two 3-glucuronide conjugates of 6β-hydroxyandrosterone (6OH-And-3G 2 ) and 6β-hydroxyetiocholanolone (6OH-Etio-3G 3 ) is reported. The conjugates are identified as long-term markers of endogenous androgenic anabolic steroid abuse in doping control studies. Their resistance to enzymatic hydrolysis by E. coli β-glucuronidase means they may be missed by conventional GC-MS analysis

A new protocol to access CF3-containing bispiro[isoquinolone-pyrrolidine-benzothiophenone]s was described. A series of 1,3-dipoles were synthesized from isoquinolinetrione and CF3CH2NH2. In the presence of 10mol% DABCO, the 1,3-dipolar cycloaddition of isoquinolinedione trifluoroethyl ketimines and unsaturated benzothiophenones delivered corresponding adducts in excellent yields (up to 98%) and di

Herein, an efficient method for vinyl or aryl C(sp 2 )-O bond forming to construct both the ( Z )-2-iodovinyl aryl ethers and diaryl ethers under metal-, photocatalyst- and light-free condition in one-step, has been developed. To generate the two desired products, we proposed a S NAr 2 reaction of phenol with vinyl aryl iodonium salts intermediates that subsequently lead to the phenyl-I bond cleavage

A novel EDA complex comprised of a bis(chlorodifluoroacetoxy)iodoarene and 1,3,5-trimethoxybenzene is described, which under monochromatic visible-light irradiation enables the direct radical C(sp2)–H chlorodifluoromethylation of arenes and heteroarenes. The procedure is mild, operationally simple, and utilizes commercially available reagents. The developed conditions demonstrate compatibility with

Easy accessible isoxazol-5(4 H )-ones are useful precursors of heterocycles. In this context we report the ruthenium-catalyzed transformation of 4-alkenyl-substituted isoxazol-5-ones to afford 1 H -pyrrole derivatives. The operative conditions were proven to be effective also on cyclohexane-fused isoxazolones giving 4,5,6,7-tetrahydroindoles. Reactions, which allow access to tri-and tetra-substituted

Formamide as the safe cyano source! A Ni-catalyzed cyanation of unactivated allylic alcohols and formamide to provide various α,β-unsaturated nitriles is developed, by generating cyano unit in situ. from safe and readily available formamide.

Various isocyanide-based multicomponent reactions prove to be highly reliable when β-substituted β-amino boronic esters are employed as the amine component, allowing the efficient synthesis of unprecedented peptidomimetics and heteroatom-rich boron-containing small molecules. In particular, the scope of the Ugi reaction is widely exploited, to give a family of enantiopure β-substituted β-amido boronates

A good Hammett correlation has been found between the two principal fragmentations of four series of ionized 2-substituted benzanilides of general structure XC 6 H 4 NHCOC 6 H 4 Y [X = CH 3 O, Cl, Br or I; Y = H, F, Cl, Br, I, CH 3 , CH 3 O, CF 3 or NO 2 in the 3 or 4 position]. When X is electron-donating, with a negative substituent constant, σ, simple cleavage to form a substituted benzoyl cation

The manuscript deals with the concise chemical synthesis of the trisaccharide repeating unit of the O-antigen from Pseudomonas putida BIM B-1100 in the form of its aminoethyl glycoside through a linear strategy with rational protecting group manipulations. The challenging aspects of this synthesis include the incorporation of the β-D-ManpNAcA and the α-D-GlcpNAc residues. The introduction of the desired

The chemical reagents used to achieve a predictable and programmable time-control of the pH of water solutions are reviewed with the purpose to present a toolbox of instruments to be used when a precise pH vs time profile is needed . Such tools are particularly useful in view of the growing interest on dissipative systems, many of which operate in water solution, under the action of reagents (chemical

Metal corrole catalyzed Baeyer-Villiger oxidation reaction was successfully achieved for the first time. Among all tested Co, Mn, Fe and Cu complexes of 5, 10, 15-Tris (pentafluorophenyl) corrole, Fe complex [Fe(tpfc)Cl] exhibited the best activity and the highest yield was observed for six membered cyclic ketones. Preliminary results suggest that Fe(tpfc)Cl may act as an initiator for dehydrogenation

2,6-Disubstituted cuneane has potential as a p -disubstituted benzene bioisostere and a novel chiral scaffold. It is a constitutional isomer of a 1,4-disubstituted cubane obtained via a metal-catalyzed skeletal rearrangement. Unlike the highly symmetrical 1,4-disubstituted cubane, the isomerized 2,6-disubstituted cuneane is a chiral molecule possessing C 2 symmetry. Examining various chiral catalysts

CuCl catalyzed the reaction of aryl boronic acid with carbon dioxide to form carboxylate ester after treatment with CH3I has been developed. The method has mild conditions and a good functional group tolerance. A diverse range of aryl boronic acids were effectively converted into carboxylate esters. Even those bearing sensitive groups such as carbonyl, ester, and amide could offer the desired products

As a common and integral feature of many natural products, thiocarboxylates play an important role in biologically or pharmaceutically active compounds. It shows the unique physiological activity in biology and drugs, which allows many new therapeutic drugs to be discovered. The related research and developments in thioester-based medicinal chemistry have been a rapidly developing and increasingly

Based on C-H activation relay (CHAR), a TBN/O 2 initiated sp 3 C-H multifunctionalization of α-cyanotetrahydroisoquinolines was developed. This reaction is superior in mild reaction conditions and good functional group tolerance, avoiding the use of strong oxidants to oxidize the inert sp 3 C-H bond.

Organoboron compounds have extreme potential for organic synthesis. Ready functionalization of organoboron intrigued people to develop various protocols for their synthesis. Over the last several decades, there has been a substantial development in synthesizing new organoboron compounds using transition metals. Among various transition metals, zirconium has also been found to catalyze diverse reactions

A convergent route for the synthesis of BCX-1777 and BCX-4430 from a Boc-protected 2-pyrrolidinone, derived from 2,3,5-tri- O -benzyl- d -ribonolactone, and a dihalogenated pyrrolopyrimidine as the key starting materials is reported. A chemoselective cross-coupling was achieved from the two key starting materials in 79% yield. Luche reduction and mesylation resulted in the stereoselective formation

A new copper/I 2 -catalyzed hydro xyamination of alkenes of unsaturated keto oximes with DMSO as the hydroxy oxygen atom source and medium for assembling 2-(2-hydroxyalkyl)-3,4-dihydro-2 H -pyrrole 1-oxides is described. Mechanistic study experiments suggest that the reaction is terminated by single electron oxidation and subsequent nucleophilic reaction.

Dependence of the hydrolysis rate of a series of N -methoxy-2-phenyl-1,3-oxazinanes on the Hammett substituent constant of the substituent of the phenyl ring was determined, yielding a reaction constant ρ = -1.40 ± 0.05. Based on this information, 4-(benzoyloxy)benzaldehyde was selected as a protecting group for a new (2 R ,3 S )-4-(methoxyamino)butane-1,2,3-triol phosphoramidite building block. The

Over the last few decades, primary and secondary amines have been enormously used to trigger numerous valuable transformations. Likewise, modern-day chemistry has witnessed the potentiality of visible-light photoredox catalysis via single photoelectron transfer reactions. Recently, their synergistic effect has proved to be a crucial synthetic pillar, as several elegant protocols have their accessibility

Concomitant selective dehydroxylation during the transformation of flavones into pyrazoles with hydrazine is determined by the A-ring substitution pattern and propensity to keto enol tautomerization. The obtained pyrazoles show varied tyrosinase inhibition properties, including one nanomolar inhibitor.

The efficient construction of quaternary carbon center is a formidable challenging task due to their enhanced structural complexity. Although the catalytic gem- difunctionalization of α -diazo carbonyl compounds via metal-carbenoids is a well-documented, developing new methods to access quaternary carbon centers which are difficult or unattainable in monocatalysis is highly desirable. Dual catalysis