SYNTHESES AND POLYMERIZATION OF α-TRIMETHYLSILYL ACRYLIC MONOMERS

1963 ◽  
Vol 41 (12) ◽  
pp. 2977-2982 ◽  
Author(s):  
Ariel Ottolenghi ◽  
Mati Fridkin ◽  
A. Zilkha
Keyword(s):  
Free Radicals ◽  
Double Bond ◽  
Methyl Ester ◽  
Acrylic Acid ◽  
Anionic Polymerization ◽  
Good Yield ◽  
Steric Effect ◽  
Trimethylsilyl Group ◽  
Acrylic Monomers

α-Trimethylsilyl acrylic acid and its methyl ester were prepared in good yield starting from 1,2-dibromoethyltrimethylsilane. These monomers were polymerized with difficulty by free radicals to viscous polymers, but gave solid copolymers with styrene. The methyl ester was also a weak monomer in anionic polymerization. This non-reactivity is due to the steric effect of the α-trimethylsilyl group adjacent to the double bond.

The reaction between 2,3-Diphenyl-2H-azirine and Phenyldiazomethane

1973 ◽  
Vol 26 (11) ◽  
pp. 2547 ◽  
Author(s):  
JH Bowie ◽  
B Nussey ◽  
AD Ward
Keyword(s):  
Double Bond ◽  
Good Yield ◽  
Alternative Synthesis

The reaction between 2,3-diphenyl-2H-azirine and phenyldiazomethane produces the stable 1-azido-1,2,3-triphenylprop-1-ene in good yield. The structure is confirmed by an alternative synthesis which indicates that the double bond has the E-configuration.

scholarly journals Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene: a general intramolecular Diels–Alder approach to tricyclic sesquiterpenes

1985 ◽  
Vol 63 (4) ◽  
pp. 993-995 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis
Keyword(s):  
Double Bond ◽  
Methyl Ester ◽  
Total Synthesis ◽  
Ring System ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
Total Syntheses ◽  
Methyl Group ◽  
Secondary Hydroxyl ◽  
Selective Hydrogenolysis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.

scholarly journals Anionic polymerization of (meth)acrylic monomers. 7. Macrocyclic crown ethers as promoters of the living polymerization of methyl methacrylate using monofunctional initiators

1992 ◽  
Vol 25 (18) ◽  
pp. 4457-4463 ◽  
Author(s):  
Sunil K. Varshney ◽  
Robert Jerome ◽  
Philippe Bayard ◽  
Christian Jacobs ◽  
Roger Fayt ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Crown Ethers ◽  
Anionic Polymerization ◽  
Living Polymerization ◽  
Acrylic Monomers

scholarly journals Nighttime oxidation of surfactants at the air–water interface: effects of chain length, head group and saturation

2018 ◽  
Vol 18 (5) ◽  
pp. 3249-3268 ◽  
Author(s):  
Federica Sebastiani ◽  
Richard A. Campbell ◽  
Kunal Rastogi ◽  
Christian Pfrang
Keyword(s):  
Oleic Acid ◽  
Double Bond ◽  
Methyl Ester ◽  
Reaction Kinetics ◽  
Chain Length ◽  
Rate Coefficients ◽  
Head Group ◽  
Water Interface ◽  
Organic Monolayers ◽  
Air Water Interface

Abstract. Reactions of the key atmospheric nighttime oxidant NO3 with organic monolayers at the air–water interface are used as proxies for the ageing of organic-coated aqueous aerosols. The surfactant molecules chosen for this study are oleic acid (OA), palmitoleic acid (POA), methyl oleate (MO) and stearic acid (SA) to investigate the effects of chain length, head group and degree of unsaturation on the reaction kinetics and products formed. Fully and partially deuterated surfactants were studied using neutron reflectometry (NR) to determine the reaction kinetics of organic monolayers with NO3 at the air–water interface for the first time. Kinetic modelling allowed us to determine the rate coefficients for the oxidation of OA, POA and MO monolayers to be (2.8±0.7) × 10−8, (2.4±0.5) × 10−8and (3.3±0.6) × 10−8 cm2 molecule−1 s−1 for fitted initial desorption lifetimes of NO3 at the closely packed organic monolayers, τd, NO3, 1, of 8.1±4.0, 16±4.0 and 8.1±3.0 ns, respectively. The approximately doubled desorption lifetime found in the best fit for POA compared to OA and MO is consistent with a more accessible double bond associated with the shorter alkyl chain of POA facilitating initial NO3 attack at the double bond in a closely packed monolayer. The corresponding uptake coefficients for OA, POA and MO were found to be (2.1±0.5) × 10−3, (1.7±0.3) × 10−3 and (2.1±0.4) × 10−3, respectively. For the much slower NO3-initiated oxidation of the saturated surfactant SA we estimated a loss rate of approximately (5±1) × 10−12 cm2 molecule−1 s−1, which we consider to be an upper limit for the reactive loss, and estimated an uptake coefficient of ca. (5±1) × 10−7. Our investigations demonstrate that NO3 will contribute substantially to the processing of unsaturated surfactants at the air–water interface during nighttime given its reactivity is ca. 2 orders of magnitude higher than that of O3. Furthermore, the relative contributions of NO3 and O3 to the oxidative losses vary massively between species that are closely related in structure: NO3 reacts ca. 400 times faster than O3 with the common model surfactant oleic acid, but only ca. 60 times faster with its methyl ester MO. It is therefore necessary to perform a case-by-case assessment of the relative contributions of the different degradation routes for any specific surfactant. The overall impact of NO3 on the fate of saturated surfactants is slightly less clear given the lack of prior kinetic data for comparison, but NO3 is likely to contribute significantly to the loss of saturated species and dominate their loss during nighttime. The retention of the organic character at the air–water interface differs fundamentally between the different surfactant species: the fatty acids studied (OA and POA) form products with a yield of  ∼ 20 % that are stable at the interface while NO3-initiated oxidation of the methyl ester MO rapidly and effectively removes the organic character ( ≤ 3 % surface-active products). The film-forming potential of reaction products in real aerosol is thus likely to depend on the relative proportions of saturated and unsaturated surfactants as well as the head group properties. Atmospheric lifetimes of unsaturated species are much longer than those determined with respect to their reactions at the air–water interface, so they must be protected from oxidative attack, for example, by incorporation into a complex aerosol matrix or in mixed surface films with yet unexplored kinetic behaviour.

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