- Alkyl monolayers on silicon prepared from 1-alkenes and hydrogen-terminated silicon
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High-quality alkyl monolayers on silicon have been prepared from 1-alkenes and hydrogen-terminated Si(111). The 1-alkenes form monolayers upon free-radical initiation with diacyl peroxides. Heat also initiates monolayer formation, although monolayers prepared from heated long-chain 1-alkenes are of lower quality than those prepared with free-radical initiation. Even when a high concentration of diacyl peroxide is used to initiate monolayer formation, the 1-alkene is the primary constituent of the monolayer. Alkynes also form monolayers on silicon when initiated by diacyl-peroxides. X-ray reflectivity shows that the monolayer thickness is of molecular dimensions and that the density is close to that of crystalline hydrocarbons (～90%). Infrared spectroscopy shows that the alkyl chains in the monolayers are densely packed. Infrared dichroism shows that the chains are tilted from the surface normal and twisted about their axes. The wetting properties of the monolayers show that they are methyl terminated. After many weeks of air exposure, the silicon substrate under the monolayers is not significantly oxidized. The monolayers are very stable to boiling chloroform, boiling water, boiling acidic and basic solutions, and fluoride and are at least as stable as similar chain-length monolayers prepared from trichlorosilanes on oxidized silicon. We propose that alkyl chains in the monolayers are bound to the silicon substrate through silicon-carbon bonds and compare a proposed mechanism of bond formation to analogous homogeneous reactions.
- Linford, Matthew R.,Fenter, Paul,Eisenberger, Peter M.,Chidsey, Christopher E. D.
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- Radical Nature of Pathways to Alkene and Ester from Thermal Decomposition of Primary Alkyl Diacyl Peroxide
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Thermal decomposition of a primary alkyl diacyl peroxide 2 is investigated.Dependence of product yields on temperature, viscosity, and solvent polarity is examined in a variety of media.The excess of the alkene disproportionation product 4 and the presence of ester 3 and acid 5 is argued to demonstrate the existence of a discrete acyloxy-alkyl geminate radical pair.Stereoselective deuterium labeling of 2 and subsequent 1H-NMR analysis of the resulting isotopomers of 4 confirm the radical nature of detected decomposition products.
- Ryzhkov, Lev R.
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- Decarboxylative C(sp3)?N cross-coupling of diacyl peroxides with nitrogen nucleophiles
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We have disclosed a new radical-mediated decarboxylative C(sp3)?N cross-coupling of diacyl peroxides with nitrogen nucleophiles. The primary and secondary alkyl radicals derived from corresponding diacyl peroxides were generated by copper catalysis or by merging copper catalysis and photoredox catalysis, respectively. Various N-alkyl nitrogen nucleophiles, including indazoles, triazoles, indoles, purine, carbazole, anilines, and sulfonamide, were provided with a broad substrate scope and good functional group tolerance.
- Tang, Zi-Liang,Ouyang, Xuan-Hui,Song, Ren-Jie,Li, Jin-Heng
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supporting information
p. 1000 - 1004
(2021/02/06)
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- Iron-Catalyzed Regioselective Decarboxylative Alkylation of Coumarins and Chromones with Alkyl Diacyl Peroxides
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A facile iron-catalyzed decarboxylative radical coupling of alkyl diacyl peroxides with coumarins or chromones has been developed, affording a highly efficient approach to synthesize a variety of α-alkylated coumarins and β-alkylated chromones. The reaction proceeded smoothly without adding any ligand or additive and provided the corresponding products containing a wide scope of functional groups in moderate to excellent yields. This protocol was highlighted by its high regioselectivity, readily available starting materials, and operational simplicity.
- Jin, Can,Sun, Bin,Xu, Tengwei,Yan, Zhiyang,Zhang, Xun
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supporting information
p. 1585 - 1591
(2019/08/07)
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- METHOD FOR PRODUCING POWDERED LAUROYL PEROXIDE
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The present application relates to a method for producing powdered lauroyl peroxide which is characterised in that a reaction mixture is used which comprises water, lauric acid chloride, hydrogen peroxide, an inorganic base and an alkane.
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Paragraph 0049
(2018/03/25)
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- Peroxide and lauroyl have intermediate in the synthesis of (by machine translation)
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The invention discloses peroxide and lauroyl have intermediate in the synthesis method, comprises the following steps: in the reaction container adding lauryl alkyl amide, 3 - methyl pentane solution, the stirring speed is 230 - 260 rpm, control temperature of the solution to 20 - 26 °C, adding aqueous solution, benzyl methyl ether solution, in the 20 - 40 min batch adding chromium acid zinc powder, to continue the reaction 80 - 120 min; then adding sodium sulfate solution, raising the temperature of the solution to 50 - 55 °C, joined four lead acetate, continue to reaction 2 - 3 h, reduce the temperature of the solution to 5 - 9 °C, adding potassium nitrate solution to wash the 20 - 40 min, adding chloropropanes solution to wash the 30 - 50 min, a solution of cyclohexanol in the recrystallization, the dehydrating agent and dehydration, to get finished peroxide and lauroyl. (by machine translation)
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Paragraph 0013; 0016-0027
(2018/07/30)
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- Iron-Catalyzed Radical Decarboxylative Oxyalkylation of Terminal Alkynes with Alkyl Peroxides
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An iron-catalyzed oxyalkylation of alkynes with alkyl peroxides as the alkylating reagents has been investigated. Alkyl peroxides are readily available from aliphatic acids and serve simultaneously as the alkylating reagents and internal oxidants. Primary, secondary, and tertiary alkyl groups of aliphatic acids were readily incorporated into C?C triple bonds and diverse α-alkylated ketones were synthesized. Mechanism studies revealed that this reaction involves highly reactive alkyl free radicals. A unique equilibrium between lauric acid and water catalyzed by the iron(III) catalyst was observed.
- Zhu, Xiaotao,Ye, Changqing,Li, Yajun,Bao, Hongli
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supporting information
p. 10254 - 10258
(2017/08/07)
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- Solvent effects on the rate of thermolysis of lauroyl peroxide
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Thermolysis of lauroyl peroxide in various organic solvents was studied. It was shown that the primary homolytic dissociation of the peroxide group is accompanied by secondary reactions of chain-induced decomposition. The reaction medium affects the rate of both the primary homolytic dissociation and secondary induced decomposition processes. Correlation equations between the rate constants of the reactions in study and the physicochemical parameters of the solvents were proposed.
- Dutka,Midyana,Dutka, Yu. V.,Pal'Chikova, E. Ya.
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p. 2703 - 2709
(2016/02/18)
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