Tag: M.W=150-200

Shu, Wei; Garcia-Dominguez, Andres; Quiros, M. Teresa; Mondal, Rahul; Cardenas, Diego J.; Nevado, Cristina published the artcile< Ni-Catalyzed Reductive Dicarbofunctionalization of Nonactivated Alkenes: Scope and Mechanistic Insights>, Quality Control of 151259-38-0, the main research area is nickel catalyzed reductive carbofunctionalization alkene scope mechanism.

Olefins devoid of directing or activating groups have been dicarbofunctionalized here with two electrophilic carbon sources under reductive conditions. Simultaneous formation of one C(sp3)-C(sp3) and one C(sp3)-C(sp2) bond across a variety of unbiased π-systems proceeds with exquisite selectivity by the combination of a Ni catalyst with TDAE as sacrificial reductant. Control experiments and computational studies revealed the feasibility of a radical-based mechanism involving, formally, two interconnected Ni(I)/Ni(III) processes and demonstrated the different ability of Ni(I) species (Ni(I)I vs PhNi(I)) to reduce the C(sp3)-I bond. The role of the reductant was also investigated in depth, suggesting that a one-electron reduction of Ni(II) species to Ni(I) is thermodynamically favored. Further, the preferential activation of alkyl vs aryl halides by ArNi(I) complexes as well as the high affinity of ArNi(II) for secondary over tertiary C-centered radicals explains the lack of undesired homo- and direct coupling products (Ar-Ar, Ar-Alk) in these transformations.

Journal of the American Chemical Society published new progress about Alkadienes Role: RCT (Reactant), RACT (Reactant or Reagent). 151259-38-0 belongs to class esters-buliding-blocks, and the molecular formula is C11H19NO2, Quality Control of 151259-38-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Campbell, Shirley E.; Comer, Murray C.; Derbyshire, Paul A.; Despinoy, Xavier L. M.; McNab, Hamish; Morrison, Roderick; Sommerville, Craig C.; Thornley, Craig published the artcile< Synthesis of pyrrolizin-3-ones by flash vacuum pyrolysis of pyrrol-2-ylmethylidene Meldrum's acid derivatives and 3-(pyrrol-2-yl)propenoic esters>, COA of Formula: C8H9NO3, the main research area is pyrrolizinone preparation flash vacuum pyrolysis; flash vacuum pyrolysis pyrrolylmethylidene Meldrums acid; pyrrolylpropenoic ester flash vacuum pyrolysis; pyrolysis flash vacuum Meldrums acid pyrrolylpropenoate.

Monosubstituted pyrrolizin-3-ones, e.g., I (R1 = Me, H, R5 = CO2Et, Ph, H, R6 = Ph, H, R7 = Me, OMe, CO2Me, Ph, H) with substituents at the 1-, 5-, 6- or 7-positions are prepared in excellent yield by flash vacuum pyrolysis (FVP) of appropriate Meldrum’s acid derivatives The mechanism involves formation of the pyrrol-2-ylmethylideneketene , which can also be generated thermally from 3-(pyrrol-2-yl)propenoate esters. This alternative route has been used to make a range of 2-substituted pyrrolizin-3-ones, again in excellent yield. The 3-oxo-3H-pyrrolizine-2-carboxylic acid could not be made in this way owing to facile decarboxylation to pyrrolizinone I, and extension to the formation of the azaazulenone II was again unsuccessful.

Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry published new progress about 7126-50-3. 7126-50-3 belongs to class esters-buliding-blocks, and the molecular formula is C8H9NO3, COA of Formula: C8H9NO3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Shariff, Azim; McLean, Stewart published the artcile< The synthesis of Nauclea indole-pyridine alkaloids. 3,4-Disubstituted and 3,4,5-trisubstituted pyridines as synthetic intermediates; a total synthesis of (±)-decarbomethoxy-3α- and -3β-nauclechine>, Quality Control of 33402-75-4, the main research area is nauclechine decarbomethoxy epimer synthesis; pyridine substituted; pyridineacetic acid substituted Bischler Napieralski; Nauclea indole pyridine alkaloid.

Synthetic routes to a number of 3,4-disubstituted and 3,4,5-trisubstituted pyridines was explored. These pyridines, designed to be used in the synthesis of Nauclea indole-pyridine alkaloids, are potentially useful intermediates in a number of syntheses. Substituted 4-pyridineacetic acids were prepared and the exptl. limitations associated with their synthesis and use in subsequent reactions such as the Bischler-Napieralski cyclization were discussed. A synthesis of decarbomethoxynauclechine from 4-methylnicotinaldehyde avoiding these difficulties was described. (±)-Decarbomethoxy-3α-nauclechine (I; R = α-H) and (±)-decarbomethoxy-3β-nauclechine (I; R = β-H) were obtained and their structure and stereochem. were established, but it was not possible to demonstrate which corresponded to the natural alkaloid, decarbomethoxynauclechine.

Canadian Journal of Chemistry published new progress about Alkaloids Role: SPN (Synthetic Preparation), PREP (Preparation). 33402-75-4 belongs to class esters-buliding-blocks, and the molecular formula is C8H9NO2, Quality Control of 33402-75-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Fife, Thomas H.; Duddy, Neil W. published the artcile< Intramolecular aminolysis of esters. Cyclization of esters of (o-aminophenyl)acetic acid>, Computed Properties of 30095-98-8, the main research area is kinetics cyclization aminophenylacetate base catalysis; mechanism cyclization aminophenylacetate LFER; oxindole; leaving group effect intramol aminolysis; proton transfer cyclization mechanism aminophenylacetate.

Rate constants are obtained for the cyclization of o-H2NC6H4CH2CO2R [R = Me (I), CF3CH2 (II)], or its protonated analog, to give III. The second order rate constant, kOH, for OH- catalysis of the reaction of I is 100-fold greater than that for the OH- catalyzed hydrolysis of PhCH2CO2Me. The kOH for cyclization of II is 85-fold greater, at 30°, than that of I. The bell shaped log k0 vs. pH profile for II at low pH indicates that the rate-determining step changes with pH and that the cyclization involves a tetrahedral addition product as an intermediate. The curved kobserved vs. buffer concentration plots for the cyclization of I at pH <7 (which indicates a buffer concentration dependence of the rate-determining step) supports this and shows that at pH >4 and low buffer concentration the breakdown of the tetrahedral intermediate is rate-determining The general base catalysis observed in the cyclization reaction of I and II (characterized by Broensted β 0.5 and 0.1, resp.) involves a proton transfer concerted with bond breaking in contrast with similar reactions of o-H2NCH2C6H4CO2Me [in which proton-transfer is rate-determining (β 1.0)]. The decrease in β as the leaving group improves indicates that the general base is partially removing a proton from the neutral tetrahedral intermediate as the C-O bond breaks. Several different mechanisms and/or rate-determining steps are possible (and are observed) in the intramol. aminolysis of aliphatic esters; the key features in these aminolysis reaction mechanisms are the nucleophile pKa, the steric fit of the nucleophile to the CO group, and the ease of C-O bond breaking in the tetrahedral intermediate decomposition to products.

Journal of the American Chemical Society published new progress about Amino esters Role: RCT (Reactant), RACT (Reactant or Reagent). 30095-98-8 belongs to class esters-buliding-blocks, and the molecular formula is C9H9NO4, Computed Properties of 30095-98-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Tararov, Vitali I.; Koenig, Gerd; Boerner, Armin published the artcile< Synthesis of statins. I. Synthesis and highly stereoselective hydrogenation of the statin precursor ethyl (5S)-5,6-isopropylidenedioxy-3-oxohexanoate>, Category: esters-buliding-blocks, the main research area is statin intermediate isopropylidenedioxyoxohexanoate preparation stereoselective hydrogenation.

A search for the large-scale preparation of (5S)-5,6-(isopropylidenedioxy)-3-oxohexanoate, a key intermediate in the synthesis of pharmacol. important statins, starting from (S)-malic acid is described. The synthesis of the required intermediate Me (3S)-3,4-(isopropylidenedioxy)butanoate (I) by Moriwake’s reduction of di-Me (S)-malate has been improved. Direct 2-C chain elongation of ester I using the lithium enolate of tert-Bu acetate has been shown to be successful at a 3- to 5-fold excess of the enolate. Unfortunately, the product, tert-Bu (5S)-5,6-(isopropylidenedioxy)-3-oxohexanoate is unstable during distillation Et (5S)-5,6-(isopropylidenedioxy)-3-oxohexanoate (II) was prepared alternatively on a multigram scale from (3S)-3,4-(isopropylidenedioxy)butanoic acid by activation with N,N’-carbonyldiimidazole and subsequent reaction with Mg(O2CCH2CO2Et)2. A convenient pathway for the in situ preparation of the latter is also described. II can be advantageously purified by distillation The stereochem. of the catalytic hydrogenation of II to Et (5S)-5,6-(isopropylidenedioxy)-3-hydrohyhexanoate (III) has been studied using a number of homogeneous achiral and chiral Rh(I) and Ru(II) complexes with phosphine ligands. A comparison of Rh(I) and Ru(II) catalysts with (S)- and (R)-BINAP as chiral ligands revealed opposite activity in dependence on the polarity of the solvent. No influence of the chiral backbone of substrate II on the enantioselectivity was noted. A ratio of syn/anti-III = 2.3 was observed with an achiral (Ph3P)3RuCl2 catalyst. Ru[(R)-Tol-BINAP]Cl2 neutralized with one equivalent of AcONa afforded the most efficient catalytic system for the production of optically pure syn-III at a preparative substrate/catalyst ratio of 1000:1.

Advanced Synthesis & Catalysis published new progress about Hydrogenation catalysts, stereoselective. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Singh, Ravi P.; Aziz, Marian N.; Gout, Delphine; Fayad, Walid; El-Manawaty, May A.; Lovely, Carl J. published the artcile< Novel thiazolidines: Synthesis, antiproliferative properties and 2D-QSAR studies>, Name: 4-tert-Butylphenylisothiocyanate, the main research area is imino methoxybenzylidene thiazolidine thiazolidinone preparation antiproliferative human QSAR; 2D-QSAR; HCT-116; One-pot; Tandem reaction.

A series of N-substituted (Z)-2-imino-(5Z)-ylidene thiazolidines and (Z)-2-imino-(5Z)-ylidene thiazolidin-4-ones were synthesized and their antiproliferative activities against colon (HCT-116) and breast (MCF7) cancer cell lines were evaluated utilizing an MTT growth assay. A 2D-QSAR investigation was conducted to probe and validate the obtained antiproliferative properties for the thiazolidine derivatives The majority of the thiazolidines exhibit higher potency against a colon cancer cell line relative to the standard reference The p-halophenylimino p-anisylidene derivatives exhibited the highest anti-proliferative activity against HCT116 relative to control (IC50 = 8.9-10.0μM compared to 20.4μM observed for 5-fluorouracil as pos. control). An X-ray study confirmed the Z,Z’-configurations for two examples of the synthesized compounds

Bioorganic & Medicinal Chemistry published new progress about Amines, propargyl Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 19241-24-8 belongs to class esters-buliding-blocks, and the molecular formula is C11H13NS, Name: 4-tert-Butylphenylisothiocyanate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Chinta, Satya P.; Goller, Stephan; Lux, Julia; Funke, Sebastian; Uhl, Gabriele; Schulz, Stefan published the artcile< The Sex Pheromone of the Wasp Spider Argiope bruennichi>, Application In Synthesis of 617-55-0, the main research area is trimethyl methylcitrate sex pheromone spider; methylcitrate diastereomer stereoselective enantioselective preparation identification pheromone wasp spider; argiope bruennichi sex pheromone identification methylcitrate diastereomer.

We investigated the pheromone system of the very characteristic wasp spider Argiope bruennichi, which lives on meadows in the Mediterranean but occurs now also in the temperate zone of middle Europe. Headspace sampling of odors emitted by individual female spiders was performed with activated charcoal traps using glass chambers containing the spiders in 3 developmental stages (subadult, virgin, and mated). The sex pheromone of the wasp spider was identified as a mixture of the 2R,3S- and 2S,3S- isomers of tri-Me methylcitrate. This pheromone is able to attract male spiders in the field in a concentration-dependent manner. Another female-specific spider compound, 3-octanoyloxy-γ-butyrolactone, was identified, but its function remains to be established.

Angewandte Chemie, International Edition published new progress about Argiope bruennichi. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Application In Synthesis of 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Aziz, Marian N.; Patel, Arzoo; Iskander, Amany; Chini, Avisankar; Gout, Delphine; Mandal, Subhrangsu S.; Lovely, Carl J. published the artcile< One-Pot Synthesis of Novel 2-Imino-5-Arylidene-Thiazolidine Analogs and Evaluation of Their Anti-Proliferative Activity against MCF7 Breast Cancer Cell Line>, Related Products of 19241-24-8, the main research area is iminoarylidine thiazolidine analog human breast cancer cell antiproliferative activity; X-ray; cytotoxicity; hydrothiolation; propargyl amine; surface-mediated cyclization.

An efficient surface-mediated synthetic method to facilitate access to a novel class of thiazolidines is described. The rationale behind the design of the targeted thiazolidines was to prepare stable thiazolidine analogs and evaluate their anti-proliferative activity against a breast cancer cell line (MCF7). Most of the synthesized analogs exhibited increased potency ranging from 2-15-fold higher compared to the standard reference, cisplatin. The most active thiazolidines contain a halogenated or electron withdrawing group attached to the N-Ph ring of exocyclic 2-imino group. However, combination of the two substituents did not enhance the activity. The anti-proliferative activity was measured in terms of IC50 values using an MTT assay.

Molecules published new progress about Antiproliferative agents. 19241-24-8 belongs to class esters-buliding-blocks, and the molecular formula is C11H13NS, Related Products of 19241-24-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Fernandes, Alessandra A. G.; Stivanin, Mateus L.; Jurberg, Igor D. published the artcile< RuCl3/ PPh3 - Catalyzed Direct Conversion of Isoxazol-5-ones to 2,3-Disubstituted Pyridines>, Category: esters-buliding-blocks, the main research area is isoxazolone acrolein ruthenium chloride triphenyl phosphine catalyst decarboxylative heterocyclization; pyridine preparation.

A novel catalytic system employing RuCl3/ PPh3 was described for the preparation of 2,3-disubstituted pyridines starting from 3,4-disubstituted isoxazol-5-ones and acrolein. Mechanistic studies involving 31P NMR, HRMS analyses and control experiments were performed in order to supported key events and intermediates proposed for this transformation.

ChemistrySelect published new progress about Benzaldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 94-02-0 belongs to class esters-buliding-blocks, and the molecular formula is C11H12O3, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Nuriye, Ahmed Y.; Barr, Joseph published the artcile< Iodine-promoted oxidative homocoupling of methyl 2-arylacetates under equilibrium conditions using potassium tert-butoxide as a base>, Computed Properties of 30095-98-8, the main research area is phenylacetate iodine potassium tert butoxide promoter diastereoselective oxidative homocoupling; diphenylsuccinate preparation.

Iodine-promoted dimerization of enolates of Me 2-phenylacetates generated with t-BuOK under equilibrium conditions were reported. The oxidative homocoupling reaction furnished a mixture of dl and meso dimers in moderate to good yields and diastereoselectivity. Electron-withdrawing substituents on the Ph ring seem to facilitate dimerization leading to higher yields and ortho-substituted Ph acetates afford better diastereoselectivity.

Results in Chemistry published new progress about Aromatic esters Role: RCT (Reactant), RACT (Reactant or Reagent). 30095-98-8 belongs to class esters-buliding-blocks, and the molecular formula is C9H9NO4, Computed Properties of 30095-98-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics