Di Tert-butyl Research Articles

Di‐tert Butyl Peroxide‐Promoted Sequential Methylation and Intramolecular Aromatization of Isonitriles

AbstractThe di‐tert butyl peroxide (DTBP)‐promoted sequential reaction of isonitriles is developed, leading to 6‐methylphenanthridine derivatives in moderate to excellent yields. DTBP served as both promoter and methyl source. The procedure proceeds through the addition of a methyl radical derived from the peroxide to the isonitrile followed by aromatic homolytic cyclization. It tolerates a series of functional groups, such as fluoro, chloro, acetyl, methoxycarbonyl, cyano and trifluoromethyl.magnified image

Di-tert-butyl peroxide-promoted α-alkylation of α-amino carbonyl compounds by simple alkanes.

A di-tert butyl peroxide (DTBP)-promoted α-alkylation of α-amino carbonyl compounds by simple alkanes is developed, proceeding through dual sp(3) C-H bonds cleavage. The reaction was applicable for α-amino ketones and α-amino esters, providing a facile pathway for the α-functionalization of these substrates. The radical pathway is involved in this transformation.

합성 윤활유 제조를 위한 퍼옥사이드계 개시제를 이용한 이소파라핀의 단독 알킬레이션

Polyalphaolefin (PAO) is a synthetic lubricant that is superior to mineral-based lubricants in terms of physical and chemical characteristics such as low pour point (PP), and high viscosity index (VI). This paper first reports a novel preparation route for a synthetic lubricant via alkylation of isoparaffins using a peroxide initiator without olefin. Alkylation of three kinds of isoparaffins such as i-C16, i-C18, and i-C23 as well as alkylation of i-C18 with 2-pentene using di-tert butyl peroxide initiator were conducted under various conditions to confirm alkylation reaction from isoparaffins themselves i.e; Single-molecule alkylation. Various properties of each alkylates (VI and PP) were investigated as a synthetic lubricant. Single-molecule alkylation made from i-C16 a,nd i-C18 showed ultra high VI (>140) and low PP (<-30 C).

The comparison of protecting methods to the amino group in 2-Aminomethylphenylacetic acid

2-Aminomethylphenylacetic acid is an important intermediate of ceforanide, and this article compared two different protecting agents for protecting the amino group in 2-aminomethylphenylacetic acid by BOC (Di-tert butyl dicarbonate) or acetacetic ester, and compared the deprotection condition. The yield was higher when BOC was used as protecting agent, but when it was deprotected, it was more difficult than when acetacetic ester was used as protecting agent.

Efficiency Enhancement of MEH-PPV:PCBM Solar Cells by Addition of Ditertutyl Peroxide as an Additive

Improved power conversion efficiency (PCE) and stability of organic bulk heterojunction (BHJ) solar cells based on poly (2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blends are obtained by using ditert butyl peroxide (DTBP) as an additive. The effect of the DTBP contents on the performance of photovoltaic cells is investigated. The results reveal that efficiency enhancement of MEH-PPV:PCBM solar cells can be realized by carefully tuning the contents of DTBP. Compared to the control device, the optimized device with 0.5wt% DTBP additive exhibits enhanced performance with Jsc of (3.51 ± 0.21) mA/cm2, FF of (44.45 ± 0.71)%, and PCE of (1.31 ± 0.08)%, increased by 9.3%, 8.0% and 22.4%, respectively. The stability of the device is found to be improved by adding 0.5wt% of DTBP.

Construction of Tertiary Alcohols Bearing Perfluoroalkyl Chains Catalyzed by Prolinamide-Thioureas

A systematic study to evaluate the ability of various organocatalysts to catalyze the aldol reaction between acetone and 2,2,2-trifluoromethyl-1-phenylethanone was undertaken. Benchmark organocatalysts failed to catalyze this reaction. However, a prolinamide-thiourea consisting of (S)-prolinamide, (1S,2S)-diphenylethylenediamine, and (S)-di-tert butyl aspartate proved to be an efficient catalyst, providing tertiary alcohols as the products of the reaction between ketones and perfluoroalkyl ketones in high to quantitative yields and high enantioselectivities (up 81% ee) at a catalyst loading of 2 mol %.

High Performance Polymer Field-Effect Transistors Based on Thermally Crosslinked Poly(3-hexylthiophene)

The performance of polymer field-effect transistors is improved by thermal crosslinking ofpoly(3-hexylthiophene), using ditert butyl peroxide as the crosslinker. The device performance depends on the crosslinker concentration significantly. We obtain an optimal on/off ratio of 105 and the saturate field-effect mobility of 0.34cm2V−1s−1, by using a suitable ratios of ditert butyl peroxide, 0.5 wt% ofpoly(3-hexylthiophene). The microstructure images show that the crosslinked poly(3-hexylthiophene) active layers simultaneously possess appropriate crystallinity and smooth morphology. Moreover, crosslinking of poly(3-hexylthiophene) prevents the transistors from large threshold voltage shifts under ambient bias-stressing, showing an advantage in encouraging device environmental and operating stability.

Living Radical Polymerization of Styrene Derivatives Containing Trialkylmetal Groups

Fourteenth group oganometallic styrene derivatives were synthesised by nitroxide-mediated controlled radical polymerization using di-tert butyl nitroxide (A-T) as initiator. This is the first time that nitroxide-controlled radical polymerization has been successfully adapted for the synthesis of new polystyrenes bearing organometallic species with controlled molecular weights and narrow polydispersities. Monomer reactivity ratios were determined in controlled nitroxide-mediated radical copolymerization between styrene and substituted styrene. All experiments permitted the synthesis of new organometallic polymers that will be used for the development of a polymer capsule for Inertial Confinement Fusion Experiments.

Reactive incompatibility of DTBP mixed with two acid solutions

Organic peroxides are commonly employed as an initiator for polymerization, a source of free radicals, a hardener, and a linking agent. Due to its relatively weak oxygen-oxygen bond, di-tert butyl peroxide (DTBP) has been categorized as flammable type or Class III by the National Fire Protection Association (NFPA). The transport of dangerous goods (TDG) has published a warning against DTBP that it could potentially induce violent heat, explosion, fire and self-ignition under certain circumstances.

Studies on the influence of structurally different peroxides in polypropylene/ethylene alpha olefin thermoplastic vulcanizates (TPVs)

Novel thermoplastic vulcanizates (TPVs) based on polypropylene (PP) and new generation ethylene-octene copolymer (EOC) have been developed by dynamic vulcanization process, which involves melt-mixing and simultaneously crosslinking a rubber with a thermoplastic. In this paper technologically compatibilized blends of PP and EOC were dynamically vulcanized by coagent assisted peroxide crosslinking system. The effect of structurally different types of per- oxides, namely dicumyl peroxide, di-tert butyl peroxy isopropyl benzene and tert-butyl cumyl peroxide with varying con- centrations on the properties on TPVs was mainly studied. The physico-mechanical, thermal and morphological properties of these TPVs were characterized by using X-ray diffraction (XRD), differential scanning calorimeter (DSC) and scanning electron microscopy (SEM).

Synthese von Fluorsilylenolaten, Aminosilylenolaten, -ethern und Aldolkondensaten/Synthesis of Fluorosilylenolates, Aminosilylenolates, -ethers, and Aldol Condensates

Depending on the reaction conditions, ketones react with n-BuLi, tert-BuLi or lithium diisopropylamide to give enolates or alcoholates. In the reaction of tert-butylmethylketone with n-BuLi followed by fluorosilanes, the fluorosilyl-enolates H2C=C(O-SiFRR′)CMe3 (1 - 4) and fluorosilylethers Me3C(CH3)(n-C4H9)C-O-SiFRR′ (5 - 8) [R,R′ = Me (1, 5); F, CMe3 (2, 6); F, C6H5 (3, 7); F, CHMe2 (4, 8)] are formed. Using tert-butylmethylketone, n-BuLi and (Me3C)2SiF2, isobutene and the fluorosilyl-enolate of acetaldehyde H2C=CH-O-SiF(CMe3)2 (9) are obtained. Diisopropylketone reacts with Me3CLi and fluorosilanes to give the fluorosilyl-enolates Me2C=C(O-SiFRR′)CHMe2 (10, 11) and -ethers,Me3C(Me2HC)2C-O-SiFRR′ (12, 13) [R,R′ = Me (10, 11); F, CMe3 (12, 13)] whereas only the silylethers R(Me)(C6H5)C-O-SiFRR′ [R, R′, R′′ = n-C4H9, Me, Me (14); C6H5, F, Me (15)] are generated in the reaction of H3C(C6H5)C=O with lithium-alkyls and fluorosilanes. 1- Di(tert-butyl)fluorosiloxy-1-cyclohexene (16) is the product of the reaction of lithiated cyclohexanone and (Me3C)2SiF2. A side reaction of the enolate formation is often a condensation releasing water. For that reason, acyclic and cyclic siloxanes may appear as by-products, e. g. disiloxane (17) using (Me3C)2SiF2, cyclotrisiloxane (Me3C(C6H5)Si-O)3 (18) using Me3(C6H5)SiF2, or cyclotetrasiloxane (Me3CSiF-O)4 (19) using Me3CSiF3 in these reactions. Attempts to prepare the enolate of cyclopentanone in the reaction with lithium diisopropylamide lead to the formation of 2,5-dicyclopentylidenepentanone (20). The 3,5,7-triphenyl-3-methyl-4,6-hexadienephenone (21) is an aldol condensate of Me(C6H5)CO. Lithium-tert-butylmethylenolate reacts with fluorosilyl-enolates 1 - 3 or SiF4 to give bis(enolato)silanes, (H2C=C(CMe3)O-)2SiRR′ [R, R′ = Me (22); F, CMe3 (23); F, C6H5 (24);] and the tris(enolato)silanes (H2C=C(CMe3)O-)3SiR [R = C6H5 (25); F (26)]. Aminosilyl-enolates H2C=C(O-SiR′R′′-NHR)CMe3 are obtained in reactions of fluorosilyl-enolates with lithium amide [27: R= CMe3, R′= Me, R′′= Me; 28: R= C6H5, R′= F, R′′= CMe3;]. Results of the crystal structure determinations of 17, the cis-isomer of 18, one trans-isomer of 19, the pentanone 20, and the hexadienephenone 21 are reported.

Synthesis and Structure of 2,2′‐Spirobi(1,3‐benzodioxole) Derivative Prepared from 3,5‐Di(tert‐butyl)‐1,2‐benzoquinone.

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Di(tert-butyl)[(pyren-1-yl)methoxy]silyl Chloride: Synthesis and Application in Purification of Synthetic Deoxyribonucleotides

Abstract Di(tert-butyl)[(pyren-1-yl)methoxy]silyl chloride reacts selectively with the 5′-hydroxy groups in deoxynucleosides and this can be removed under conditions which do not affect other commonly used acid or base labile protecting groups, yet it, is stable to phosphorylation conditions. While incorporated terminally at 5′-OH of the long sequence viz., 26-mer, this group is also helpful in subsequent purification by HPLC as well as PAGE. Fluorescence properties of these sequences were studied to find the suitability of the approach.

Synthesis and structure of 2,2′-spirobi(1,3-benzodioxole) derivative prepared from 3,5-di(tert-butyl)-1,2-benzoquinone

Di(tert-butyl)-1,2-benzoquinone reacted with 1,2,3-trimethylbenzimidazolium iodide led to the formation of 2,2' -spirobi(4,6-di(tert-butyl)-1,3-benzodioxole). The reaction mechanism was suggested. The structure of 2,2' -spirobi(4,6-di(tert-butyl)-1,3-benzodioxole) was established by means of X-ray diffraction analysis. Scheme 1. The chemistry of sterically-hindered O-quinones is versatile and rich in unexpected paths in reactions with methylene-active compounds. We recently revealed that the reaction of the sterically-hindered O-quinones with quinaldine derivatives resulted in the formation of (quino- lin-2-yl)-1,3-tropolones (1-3). Reactions of 3,5-di(tert- butyl)-1,2-benzoquinone with 2-methylbenzimidazole derivatives gave rise to polycyclic isoquinoline derivatives (4). We extended this reaction to benzimidazolium salts, and the study of reaction products obtained from 3,5-di- (tert-butyl)-1,2-benzoquinone (I) and a salt of 1,2,3-tri- methylbenzimidazolium II by X-ray diffraction analysis demonstrated the formation of 2,2'-spirobi(4,6-di(tert- butyl)-1,3-benzodioxole) (III) in considerably high yield (65-70%) (Scheme 1). The structure of 2,2'-spirobi(4,6-di(tert-butyl)-1,3- benzodioxole) (III) has been established by X-ray crystallography and is shown on the figure. The main interatomic distances and bond angles are compiled in the table. The presumed mechanism of compound III formation is given in Scheme 2. In the first stage of the reaction quinone I adds to the N-methyl group of the benzimidazolium resulting in the formation of adduct A, whose oxidation with initial quinone I may give 3-(4,6-di(tert-butyl)-1,3-benzodioxol- 2-yl)-1,2-dimethyl-3H-benzimidazolium iodide B. Further transformation occurs probably through the addition of the second quinone I molecule to salt B leading to intermediate compound C followed by elimination of a molecule of 1,2-dimethylbenzimidazolium iodide (IV) and thus giving rise to reaction product III.

Thermal decomposition kinetic of liquid organic peroxides

This study demonstrates the application of isothermal calorimeter for investigating the thermal decomposition of several liquid organic peroxides, such as t-Butyl peroxy acetate (TBPA), Di-tert butyl peroxide (DTBP), and Cumene hydroperoxide (CHP). The decomposition mechanism and kinetic can be identified from case to case. TBPA and DTBP undergo first order reaction, whereas CHP occurs autocatalysis. Accurate kinetic can be assessed on the basis of discerning these various schemes of given samples. Consequently, the thermal runaway or reactive hazards potential of organic peroxides can be determined, for instance as a self accelerating decomposition temperature (SADT).

Free-radical chain decomposition of ozone initiated by di(tert-butyl) trioxide

Di(tert-butyl) trioxide in a solution of CFCl3 (Freon-11) at –23 °C exists in equilibrium with the tert-butoxyl and tert-butylperoxyl radicals virtually without irreversible decomposition. The above radicals decompose ozone to dioxygen with a high effective rate constant, which is proprotional to the square root of the ButOOOBut concentration. The kinetic scheme describing the found relationships was proposed.

ESR Detection of the Regioisomers Due to Addition of Methoxy and Methylthio Radicals to Fullerene C70

The authors report ESR studies of three regioisomers of the MeS-C{sub 70}{center_dot} adduct formed by photolysis. A 1:3:3:1 splitting pattern was observed for each regioisomer. A methoxy adduct of C{sub 70} was formed by photolysis of di-tert butyl peroxide in the presence of C{sub 70}, but the ESR spectra were too complicated for interpretation. Photolysis of MeOSSOMe generates an MeO{center_dot} radical which adds to C{sub 60} forming MeO-C{sub 60}{center_dot} which was studied by ESR spectrometry. 11 refs., 3 figs., 1 tab.

ChemInform Abstract: Facile Synthesis of Functional Mono‐ and Di(tert‐butyl)boron Compounds.

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Conversion of Primary Amines to N,N′-Disubstituted Ureas Using Montmorillonitebipyridinepalladium(II)-acetate and Di-Tert Butyl Peroxide

Abstract A simple and convenient methodology for the synthesis of N,N′-disubstituted ureas from primary amines by a heterogenized catalyst montmorillonitebipyridinepalladium (II)acetate for the first time at room temperature and atmospheric pressure is described.

ChemInform Abstract: Enantioselective Syntheses of α‐Amino Acids from 10‐(Aminosulfonyl)‐2‐bornyl Esters and Di(tert‐butyl) Azodicarboxylate.

ChemInform Abstract: Enantioselective Syntheses of α‐Amino Acids from 10‐(Aminosulfonyl)‐2‐bornyl Esters and Di(tert‐butyl) Azodicarboxylate.