Tag: M.W=100-150

Khutorianskyi, Andrii published the artcileDifluoromethyl Nitrile Oxide (CF₂HCNO): A Neglected Chemical Reagent, Formula: C7H13NO2, the publication is European Journal of Organic Chemistry (2017), 2017(27), 3935-3940, database is CAplus.

The synthesis of CF₂H-isoxazoles I [R = CN, C(O)CH₃, CO₂Me, etc.] via [3+2]-cycloaddition of a novel chem. reagent – difluoromethyl nitrile oxide (CF₂HCNO) in-situ generated from difluoromethylacetaldehyde oximes with alkynes/enamines was reported. These products were promising cores for agrochem. A representative CHF₂-isoxazole was incorporated into the known fungicide Fluxapyroxad and the synthesized analog showed higher antifungal activity than the parent fungicide.

European Journal of Organic Chemistry published new progress about 924-99-2. 924-99-2 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Amine,Aliphatic hydrocarbon chain,Ester, name is Ethyl 3-(dimethylamino)acrylate, and the molecular formula is C7H13NO2, Formula: C7H13NO2.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Xu, Kangming published the artcileTransparent, self-recoverable, highly tough, puncture and tear resistant polyurethane supramolecular elastomer with fast self-healing capacity via “hard-soft” hard domain design, Recommanded Product: 3-Acetyldihydrofuran-2(3H)-one, the publication is RSC Advances (2022), 12(5), 2712-2720, database is CAplus and MEDLINE.

The integration of superior mech. properties and fast healing efficiency for self-healing polyurethane supramol. elastomers is challenging due to the confliction between high chain mobility for healing and high chain rigidity for mech. properties. Herein, a strategy to design a “hard-soft” hard domain by the cooperation of quadruple hydrogen bonds (HBs) in the mainchain as restriction units and single HBs in the side chain as diffusion units is reported. The resulting transparent supramol. elastomer exhibited fast self-recoverability, good puncture resistance and superior mech. properties with a tensile strength of 20.5 MPa, an extensibility of 2043.7%, a toughness of 146.1 MJ m^-3 and a tear resistance of 13.8 kJ m^-2. Moreover, the fast self-healing capacity (healing efficiency > 82% within 3 h under moderate condition) was realized due to the soft effects of weak HBs in the side chain on the strong HBs in the mainchain. Taking advantage of the merits of the supramol. elastomer, a flexible sensor was simply fabricated, which showed good self-repairable and stable sensing properties. Thus, the elastomer has great potential in the field of flexible electronics and wearable devices.

RSC Advances published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C7H3Cl2F3O2S, Recommanded Product: 3-Acetyldihydrofuran-2(3H)-one.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Zhang, Ruijie K. published the artcileEnzymatic assembly of carbon-carbon bonds via iron-catalysed sp³ C-H functionalization, Recommanded Product: 3-Acetyldihydrofuran-2(3H)-one, the publication is Nature (London, United Kingdom) (2019), 565(7737), 67-72, database is CAplus and MEDLINE.

Although abundant in organic mols., carbon-hydrogen (C-H) bonds are typically considered unreactive and unavailable for chem. manipulation. Recent advances in C-H functionalization technol. have begun to transform this logic, while emphasizing the importance of and challenges associated with selective alkylation at a sp³ carbon. Here we describe iron-based catalysts for the enantio-, regio- and chemoselective intermol. alkylation of sp³ C-H bonds through carbene C-H insertion. The catalysts, derived from a cytochrome P 450 enzyme in which the native cysteine axial ligand has been substituted for serine (cytochrome P411), are fully genetically encoded and produced in bacteria, where they can be tuned by directed evolution for activity and selectivity. That these proteins activate iron, the most abundant transition metal, to perform this chem. provides a desirable alternative to noble-metal catalysts, which have dominated the field of C-H functionalization. The laboratory-evolved enzymes functionalize diverse substrates containing benzylic, allylic or α-amino C-H bonds with high turnover and excellent selectivity. Furthermore, they have enabled the development of concise routes to several natural products. The use of the native iron-haem cofactor of these enzymes to mediate sp³ C-H alkylation suggests that diverse haem proteins could serve as potential catalysts for this abiol. transformation, and will facilitate the development of new enzymic C-H functionalization reactions for applications in chem. and synthetic biol.

Nature (London, United Kingdom) published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C9H8BNO2, Recommanded Product: 3-Acetyldihydrofuran-2(3H)-one.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Liu, Hao-Nan published the artcileCu-Mediated Expeditious Annulation of Alkyl 3-Aminoacrylates with Aryldiazonium Salts: Access to Alkyl N²-Aryl 1,2,3-Triazole-carboxylates for Druglike Molecular Synthesis, Application In Synthesis of 30414-53-0, the publication is Organic Letters (2020), 22(4), 1396-1401, database is CAplus and MEDLINE.

A Cu-mediated annulation reaction of alkyl 3-aminoacrylates with aryldiazonium salts was described, both of which were readily available substrates. Furthermore, alkyl 2-aminoacrylates were also viable substrates. Diverse alkyl N²-aryl 1,2,3-triazole-carboxylates and their analogs was rapidly prepared under mild conditions. Especially, this protocol allowed one to access several druglike variants of carbonic anhydrase inhibitors and celecoxib.

Organic Letters published new progress about 30414-53-0. 30414-53-0 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ketone,Ester, name is Methyl 3-oxovalerate, and the molecular formula is C6H10O3, Application In Synthesis of 30414-53-0.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Sabatini, Stefano published the artcile8-Methyl-7-substituted-1,6-naphthyridine-3-carboxylic acids as new 6-desfluoroquinolone antibacterials, Recommanded Product: Ethyl 3-(dimethylamino)acrylate, the publication is Journal of Heterocyclic Chemistry (1999), 36(4), 953-957, database is CAplus.

1,6-Naphthyridine-8-methyl-7-substituted-3-carboxylic acids I (R = N-methylpiperazine, piperidine, 1,2,3,4-tetrahydroisoquinoline) were synthesized as new 6-desfluoroquinolone antibacterials in which the usual fluorine atom at C-6 position was replaced by an endocyclic nitrogen atom. The antibacterial activity of I proved less when compared to our previous 6-amino and 6-hydrogen counterparts. However, the presence of Me group at C-8 position provided good Gram-pos. antibacterial activity, with min. inhibitory concentration values on the same order of ciprofloxacin for the piperidinyl and tetrahydroisoquinolinyl derivatives

Journal of Heterocyclic Chemistry published new progress about 924-99-2. 924-99-2 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Amine,Aliphatic hydrocarbon chain,Ester, name is Ethyl 3-(dimethylamino)acrylate, and the molecular formula is C7H13NO2, Recommanded Product: Ethyl 3-(dimethylamino)acrylate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Yildirim, Muhammet published the artcileA rapid access to novel and diverse 3-oxothiazolo[3,2-c]pyrimidine-8-carboxylates using multicomponent Mannich cyclisation reactions, Product Details of C5H10O2S, the publication is Molecular Diversity (2015), 19(1), 1-13, database is CAplus and MEDLINE.

An efficient synthesis of 3-oxotetrahydrothiazolo[3,2-c]pyrimidine-8-carboxylate derivatives, e.g., I, was developed by double Mannich cyclization of 4-oxothiazolidines with formaldehyde and amines under very mild conditions. The benefits of this method involve simple and rapid one-pot multicomponent synthesis from com. available precursors, easy work-up, and excellent yields.

Molecular Diversity published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C19H14O2, Product Details of C5H10O2S.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Zhang, Zhicheng published the artcileGeneral chemoenzymatic route to two-stereocenter triketides employing assembly line ketoreductases, Quality Control of 30414-53-0, the publication is Chemical Communications (Cambridge, United Kingdom) (2020), 56(1), 157-160, database is CAplus and MEDLINE.

Modular polyketide synthases (PKSs) are enzymic assembly lines that fuse carbon fragments into complex chiral products. Here, their synthetic logic is employed to chemoenzymically generate two-stereocenter triketides. Each of the four stereoisomers was constructed in a stereocontrolled manner using C-acylation and two PKS ketoreductases possessing opposite stereoselectivities.

Chemical Communications (Cambridge, United Kingdom) published new progress about 30414-53-0. 30414-53-0 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ketone,Ester, name is Methyl 3-oxovalerate, and the molecular formula is C8H11BO2, Quality Control of 30414-53-0.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Rogers, E. F. published the artcileThe structure and toxicity of DDT insecticides, Computed Properties of 5340-78-3, the publication is Journal of the American Chemical Society (1953), 2991-9, database is CAplus.

A novel steric effect for diphenylmethanes which have a bulky substituent on the α-C atom, based on the consideration of a Fisher-Hirschfelder model of Ph₂CHCMe₃ (I), is postulated and generalized as follows: In compounds having on 1 C atom 2 or 3 planar groups and a group sufficiently large to hinder the rotation of the planar groups, although capable of rotation itself, the planar group will tend to positions of maximum clearance, i.e., to positions corresponding to the sides of a trihedral angle; this steric effect is termed trihedralization. In I the only rotation possible is that of the Me₃C group. With DDT a more complex situation arises, since it is possible to rotate 1 large group, either a p-ClC₆H₄ or the CCl₃ group, about the central C atom. Since rotation of the CCl₃ group appears to involve less strain, it is assumed that DDT has a configuration similar to that suggested for I. If the CCl₃ group of DDT has, as one of its functions, the trihedralization of the (p-ClC₆H₄)₂CH moiety, replacement of this group with other trihedralizing groups may give effective insecticides. (p-MeOC₆H₄)₂CHCMe₃ (II) was found to have insecticidal activity of the same order as the DDT analog methoxychlor [(p-MeOC₆H₄)₂CHCCl₃]. The structure-activity relationships have been explored by tests of many related, new compounds A significant lack of activity was observed with (p-MeOC₆H₄)₂CHCH₂CMe₃ (III) and [(p-ClC₆H₄)₂CHNMe₃]Br (IV). It is concluded that the basic structural requirement for insecticidal activity of the DDT type is a diphenylmethyl moiety substituted at the p,p’-positions by halogen, MeO, or Me, and joined at the central C atom to a relatively nonpolar group of sufficient bulk to hinder the rotation of the aryl rings. A flattened (trihedralized) configuration of the diphenylmethyl moiety is thereby produced, similar to the steroids in shape and length. Mol. compounds with steroids are proposed as a mechanism for transport of DDT insecticides to fatty tissue. The toxicities of DDT-type compounds can be related to the possibility of combination with steroids. Me₃CCO₂Et (65 g.) in Et₂O added to p-MeOC₆H₄MgBr (from 200 g. p-MeOC₆H₄Br) in Et₂O at 0°, the mixture warmed to room temperature, let stand 16 hrs., refluxed 4 hrs., hydrolyzed with 200 cc. 25% aqueous NH₄Cl, the Et₂O layer dried with Na₂SO₄, evaporated, the semisolid orange residue (146 g.) dissolved in boiling petr. ether, the solution cooled slowly, the crude (p-MeOC₆H₄)₂ (3.0 g.), m. 62-95° (recrystallized, m. 171-2°), filtered off, and the filtrate chilled gave 118 g. (78%) crude (p-MeOC₆H₄)₂C(OH)CMe₃ (V), m. 66-76°; m. 81-3° (from petr. ether). V could not be prepared from Me₃CMgCl with (p-MeOC₆H₄)₂CO. tert-AmMgCl with (p-MeC₆H₄)₂CO also failed to give appreciable yields of the desired alc. V (30 g.) in 100 cc. absolute EtOH, hydrogenated 3 hrs. at 250° and 6000 lb. pressure over 10 g. Ba-stabilized Cu chromite catalyst, the mixture filtered through Supercel, and the filtrate evaporated in vacuo yielded 26 g. II, m. 51-7°; recrystallized twice from petr. ether and dried over paraffin, it m. 59-61°. II (8.5 g.) and 20 g. pyridine-HCl refluxed 6 hrs. at 220° bath temperature, and the mixture cooled and treated with H₂O yielded 5.0 g. (66%) (p-HOC₆H₄)₂CHCMe₃ (VI), m. 163-4° (from C₆H₆). Me₃CCHO (3.5 g.) added at 0-5° to 50 cc. concentrated H₂SO₄ and 50 cc. glacial AcOH, the mixture treated portionwise during 20 min. with 7.5 g. PhOH, let stand 2.5 hrs. at 0-5°, poured on ice, the crude precipitate (2.9 g.), m. 124-36°, extract with 10% NaOH, and the extract acidified gave VI, m. 158-60° (from C₆H₆). SOCl₂ (16.5 g.) added dropwise with stirring to 30 g. V in 50 cc. PhMe at 0°, the mixture stirred 2 hrs. at 10°, let stand overnight at room temperature, the SOCl₂ removed, and the residue chilled gave 1.2 g. gray solid, m. 118-22°, possibly the rearranged chloride; the filtrate on distillation yielded 20 g. (71%) (p-MeOC₆H₄)₂CMeCMe:CH₂ (VII), colorless viscous oil, b₁ 165-71°, b₉ 208-9°, n²⁵_D 1.5738, d₂₅ 1.075, reacted instantly with KMnO₄ and with Br. VII hydrogenated in EtOH at room temperature over Pd-C catalyst yielded 64% (p-MeOC₆H₄)₂CMeCHMe₂ (VIII), m. 100-2° (from EtOH). VIII demethylated in refluxing HBr-AcOH gave (p-HOC₆H₆)₂CMeCHMe₂, m. 157-8°. The HCl-catalyzed condensation of PhOH and Me₂CHAc gave after 1 month at room temperature 9% p-HOC₆H₄CHMeCMe₂C₆H₄OH-p (IX), m. 198-9°. IX methylated with Me₂SO₄ and alkali and the product washed with Claisen alkali gave the di-Me ether of IX, b₇ 200-10°, n²⁵_D 1.5670, d₂₅ 1.066. Me₃CCO₂Et treated with PhMgBr yielded 53% Ph₂C(OH)CMe₃ (X), b₁ 155-61°, n²⁵_D 1.5745, d₂₅ 1.054. Reduction of X yielded Ph₂CHCMe₃ (XI). Into XI (11.2 g.) in 200 cc. CCl₄ heated with 1 g. powd. Fe to 70° was introduced 18 g. Br below the surface of the liquid in the dark during 3.5 hrs. and the mixture stirred 2 hrs. at 70°, let stand overnight at room temperature, washed with 10% alkali, dried over Na₂SO₄, and evaporated to leave 17.2 g. crude oil; distillation of a 16-g. portion of the oil gave 0.8 g. distillate at 150-64°/< 1 mm., 4 g. at 164-7°/< 1 mm., and 5 g. at 183-7°/< 1 mm.; identical runs with a Br-addition time of 4 hrs. and subsequent reaction for 7 hrs. at 55° gave 63% distillate, b₁ 200-5°, n²⁵_D 1.6012, which afforded 24% (p-BrC₆H₄)₂CHCMe₃ (XII), crystals, m. 83°. XI (45 g.) and 1 g. powd. Fe in 150 cc. CCl₄ treated 3 hrs. at 0-5° in the dark with Cl, the mixture packed in ice, allowed to warm up slowly overnight, washed with dilute H₂SO₄, and aqueous NaHCO₃, dried, and the solvent removed in vacuo gave 61 g. light yellow oil; distillation of a 51-g. sample of the crude oil gave 16.2 g. distillate, b₁ 160-7°; 20.2 g., b₁ 167-9°; and 8.6 g., b₁ 174-87°; the 1st 2 fractions are impure (p-ClC₆H₄)₂CHCMe₃. Concentrated HNO₃ (d. 1.42)(27 cc.) and 30 cc. concentrated H₂SO₄ added to 33.6 g. XI at 40-50°, the mixture heated 2 hrs. with stirring at 45-50°, poured on ice, the orange, tacky gum triturated with 5% aqueous NaHCO₃, filtered, the insoluble sticky powder milled with Et₂O, and the resulting white crystalline product, m. 135-40°, (36 g.) recrystallized from 300 cc. EtOH gave (p-O₂NC₆H₄)₂CHCMe₃, m. 145-7°, reduced in EtOH at room temperature with Pt catalyst to (p-H₂NC₆H₄)₂CHCMe₃, m. 144° (from Et₂O-petr. ether). p-FC₆H₄MgBr and Me₃CCO₂Et yielded 41% (p-FC₆H₄)₂C(OH)CMe₃ (XIV), m. 76-7° (from petr. ether). XIV hydrogenated over Cu chromite gave 87% (p-FC₆H₄)₂CHCMe₃ (XV), m. 40-50°, m. 52-5° after distillation at 110-12°/<1 mm., highly soluble in the common organic solvents. p-MeC₆H₄MgBr and Me₃CCO₂Et gave (p-MeC₆H₄)₂C(OH)CMe₃, b₁ 165-71°, n²⁵ _D 1.5640, d₂₅ 1.021; redistilled, it b_0.5 151-3°, and was reduced to 77% (p-MeC₆H₄)₂CHCMe₃ (XVI), b₁, 128°, n²⁵_D 1.5528, d₂₅ 0.959. XVI (12 g.) hydrogenated at 250° and 3500 lb. pressure 7 hrs. over Raney Ni gave 8 g. 1-p-tolyl-1-(4-methylcyclohexyl)-2,2-dimethylpropane, b_0.5 122-4°, n²⁵_D 1.5090, d₂₅ 0.915. The crude carbinol obtained from p-MeC₆H₄MgBr and Me₂CHCO₂Et was dehydrated by heating with iodine 3 hrs. at 100° to 60% (over-all) (p-MeC₆H₄)₂C:CMe₂, b₈ 160°, m. 46-7°, which was reduced to 80% (p-MeC₆H₄)₂CHCHMe₂, m. 48-9° (from MeOH). The crude carbinol from p-MeC₆H₄MgBr and 2,4-Me₂C₆H₃COCHMe₂ gave similarly 45% p-MeC₆H₄(2,4-Me₂C₆H₃)C:CMe₂, b₆ 167-8°, n²⁵_D 1.5717, d₂₅ 0.965, quantitatively reduced to p-MeC₆H₄(2,4-Me₂C₆H₃)CHCHMe₂, b₅ 158°, n²⁵_D 1.5528, d₂₅, 0.960. [p-MeOC₆H₄C(OH)Me]₂, m. 192-3°, was reduced to 40% meso(p-MeOC₆H₄CHMe)₂, m. 138° (from petr. ether). PhOMe (162 g.) treated with 266 g. AlCl₃, the complex saturated with dry HCl at 0°, treated dropwise with 36 g. Me₂CHCHO at 0° during 1 hr., the solution warmed to room temperature overnight, poured on ice, the organic layer washed with aqueous NaHCO₃, steam-distilled to remove 90 cc. PhOMe, and the residual oil fractionated yielded 56% (p-MeOC₆H₄)₂CHCHMe₂ (XVII), b₁ 177-81°. The AlCl₃-catalyzed condensation of PhOMe and Me₃CCH₂CHMeCH₂CHO yielded 30% (p-MeOC₆H₄)₂CHCH₂CHMeCH₂CMe₃, b₁ 190-6°, n²⁵_D 1.5568, d₂₅ 1.080. Me₃CCH₂CO₂Et (XVIII), b₁₀₅ 85-6°, n²⁵_D 1.4020, was prepared in good yield by conversion of diisobutylene to Me₃CCH₂Ac, which was oxidized with hypobromite to Me₃CCH₂CO₂H, and this esterified with EtOH. XVIII treated with p-MeOC₆H₄MgBr gave (p-MeOC₆H₄)₂C(OH)CH₂CMe₃ (XIX), m. 78-9° (from C₆H₆-Skellysolve D), reduced to 75% (p-MeOC₆H₄)₂CHCH₂CMe₃ (XX), m. 57-8° (from petr. ether). Me₃CMgCl and p-MeOC₆H₄CHO yielded 77% p-MeOC₆H₄CH(OH)CMe₃, b₁₂ 140°, m. 41-2°, which was reduced to 77% p-MeOC₆H₄CH₂CMe₃, b₁₀ 105-6°, n²⁵_D 1.4953. Me₃CMgCl and p-MeOC₆H₄Ac yielded 60% p-MeOC₆H₄CMe(OH)CMe₃, b₁₃ 140-6°, m. 93-4° (from Me₂CO), reduced to 60% p-MeOC₆H₄CHMeCMe₃, b₈ 102-10°. (p-MeOC₆H₄)₂CHCN, m. 154-5° (prepared from p-MeOC₆H₄CH(OH)CN and PhOMe in the presence of BF₃), with excess MeMgI, the mixture hydrolyzed, and the neutral fraction distilled yielded 48% (p-MeOC₆H₄CH₂)₂CHAc (XXI), b₃ 218-21°, m. 66-8°; oxime, m. 118-35° (from CHCl₃). (p-ClC₆H₄)₂CHBr treated with anhydrous Me₃N in MeCN at -10°, and the crude product dried in a vacuum desiccator and recrystallized from Me₂CO-petr. ether gave IV, m. 185-7°. The following compounds have been tested as contact insecticides with German cockroaches and milkweed bugs, as fabric protectants with clothes-moth and carpet-beetle larvae, and as larvicides with mosquito larvae: I, II, IV, XII, XIII, XV, XVI, XVII, XX, methoxychlor, (p-MeOC₆H₄)₂CH₂, and (p-MeOC₆H₄)₂CHMe. The results are tabulated.

Journal of the American Chemical Society published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, Computed Properties of 5340-78-3.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Pertschi, Romain published the artcileSpirocyclic Amide Acetal Synthesis by [CpRu]-Catalyzed Condensations of α-Diazo-β-Ketoesters with γ-Lactams, Application of Methyl 3-oxovalerate, the publication is Helvetica Chimica Acta (2021), 104(10), e2100122, database is CAplus.

The synthesis of spirocyclic amide acetals (33-93%) has been achieved through Ru(II)-catalyzed condensations of N-carbamate protected pyrrolidinones with metal carbenes derived from α-diazo-β-ketoesters. Thanks to the mildness of the diazo decomposition conditions induced by a 1 : 1 combination of [CpRu(MeCN)₃][BArF] and 1,10-phenanthroline, the formation of the sensitive products is possible. Full characterization of this carbonyl-ylide mediated process is provided by DFT calculations

Helvetica Chimica Acta published new progress about 30414-53-0. 30414-53-0 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ketone,Ester, name is Methyl 3-oxovalerate, and the molecular formula is C6H10O3, Application of Methyl 3-oxovalerate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Bauer, Nicole published the artcileControlled Radical Polymerization of Myrcene in Bulk: Mapping the Effect of Conditions on the System, Quality Control of 19788-49-9, the publication is ACS Sustainable Chemistry & Engineering (2017), 5(11), 10084-10092, database is CAplus.

Solvent-free reversible deactivation radical polymerization of myrcene, a naturally occurring terpenoid monomer, with high regioselectivity was developed recently. Here, this green polymerization system is further improved to reach increased yields and produce polymers with high molar mass but still low dispersity and regioregular microstructure. To this end, two initiators (dibenzoyl peroxide, DBPO; azobis(isobutyronitrile), AIBN) at 65, 90, and 130 °C were applied, and it was demonstrated that these varying conditions have a huge effect not only on the monomer conversion and the molar mass of the product, but also on the microstructure of the resulting polymyrcene. The polymerizations utilized two trithiocarbonate chain-transfer agents, and were similar in yields, molar masses, and dispersity of the produced polymyrcene, but progressed differently for the diverse initiator-temperature pairs. Generally, in all systems, pseudo-first-order kinetics, linear increase of molar mass with conversion, and low D values were found as a result of controlled polymerization The systems using AIBN and DBPO initiators at 90 and 130 °C, resp., have rate constants of propagation (k^app_p) lower than the decomposition rates (k_d) of initiators, likewise important to control the polymerizations At 130 °C, also branching occurred at the higher stage of the reaction, and lower regioregularity developed during the polymerization as a consequence of the favorable junction formation at elevated temperature and increased viscosity. Generally, compared to the previous study on the reversible deactivation radical polymerization of myrcene via reversible addition-fragmentation chain-transfer polymerization process, significantly higher conversions (30 → 65%) and increased chain length (9 → 40 kDa) were reached. The dispersity values for these polymerizations remained as low as 1.3-1.6, and also regioregular microstructures (up to 94%) were detected.

ACS Sustainable Chemistry & Engineering published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C5H10O2S, Quality Control of 19788-49-9.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics