The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
M. Frederick Hawthorne - One of the best experts on this subject based on the ideXlab platform.
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Adaptation of the Barton Reaction to Carborane Chemistry: The Synthesis and Reactivity of 2‐Hydroxyimino‐1‐hydroxymethylnona‐B‐methyl‐1,12‐dicarba‐closo‐dodecaborane(12)
Angewandte Chemie (International ed. in English), 1998Co-Authors: Axel Herzog, Carolyn B. Knobler, M. Frederick HawthorneAbstract:Just one of the ten methyl groups of deca-B-methyl-1,12-dicarba-closo-dodecarborane(12) (1) is selectively functionalized in a Reaction sequence in which photolysis of a nitrite of 1 is the key step. Reduction of the resulting aldoxime with LiAlH4 generates, by way of the first Beckmann rearrangement of a boron-substituted oxime, the methylamino alcohol 2.
Axel Herzog - One of the best experts on this subject based on the ideXlab platform.
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Adaptation of the Barton Reaction to Carborane Chemistry: The Synthesis and Reactivity of 2‐Hydroxyimino‐1‐hydroxymethylnona‐B‐methyl‐1,12‐dicarba‐closo‐dodecaborane(12)
Angewandte Chemie (International ed. in English), 1998Co-Authors: Axel Herzog, Carolyn B. Knobler, M. Frederick HawthorneAbstract:Just one of the ten methyl groups of deca-B-methyl-1,12-dicarba-closo-dodecarborane(12) (1) is selectively functionalized in a Reaction sequence in which photolysis of a nitrite of 1 is the key step. Reduction of the resulting aldoxime with LiAlH4 generates, by way of the first Beckmann rearrangement of a boron-substituted oxime, the methylamino alcohol 2.
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adaptation of the Barton Reaction to carborane chemistry the synthesis and reactivity of 2 hydroxyimino 1 hydroxymethylnona b methyl 1 12 dicarba closo dodecaborane 12
Angewandte Chemie, 1998Co-Authors: Axel Herzog, Carolyn B. Knobler, Frederick M HawthorneAbstract:Just one of the ten methyl groups of deca-B-methyl-1,12-dicarba-closo-dodecarborane(12) (1) is selectively functionalized in a Reaction sequence in which photolysis of a nitrite of 1 is the key step. Reduction of the resulting aldoxime with LiAlH4 generates, by way of the first Beckmann rearrangement of a boron-substituted oxime, the methylamino alcohol 2.
Takahide Fukuyama - One of the best experts on this subject based on the ideXlab platform.
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Encyclopedia of Radicals in Chemistry, Biology and Materials - Radical Chemistry by Using Flow Microreactor Technology
Encyclopedia of Radicals in Chemistry Biology and Materials, 2012Co-Authors: Takahide FukuyamaAbstract:In recent years, microReaction technology based on tiny microchannels and continuous flow systems has attracted increased interest because of its high potential as a Reaction apparatus ideal for chemical Reactions. This article presents an overview of the recent advances in radical Reactions, involving thermally induced and photoinduced radical Reactions, using microReaction technology, with an emphasis on the ways chemical devices can contribute to better results in ordinary synthetic radical Reactions. Keywords: microreactor; continuous flow system; radical reduction; radical cyclization; Barton-McCombie deoxygenations; radical carbonylation; radical polymerization; halogenation; photo Barton Reaction; photo–carbonylation; C–H carbonylation
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microflow photo radical Reaction using a compact light source application to the Barton Reaction leading to a key intermediate for myriceric acid a
Tetrahedron, 2009Co-Authors: Atsushi Sugimoto, Takahide Fukuyama, Yukihito Sumino, Makoto TakagiAbstract:The Barton Reaction (nitrite photolysis) of a steroidal substrate 1, to give 2, a key intermediate for the synthesis of myriceric acid A, an endothelin receptor antagonist, was successfully carried out in a continuous microflow system using a Pyrex glass-covered stainless-steel microreactor having a one lane microchannel (Type A: 1000 μm width, 107 μm depth, 2.2 m length). We found that using a low-power black light (peak wavelength: 352 nm) and UV-LED light (peak wavelength: 365 nm) as the light source will suffice for the Barton Reaction, creating a compact energy-saving photo-microReaction system. A multi-gram-scale production was attained using a multi-lane microreactor (Type B: 1000 μm width, 500 μm depth, 0.5 m length, 16 lanes) in conjunction with a black light.
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The Barton Reaction using a microreactor and black light. Continuous-flow synthesis of a key steroid intermediate for an endothelin receptor antagonist
Tetrahedron Letters, 2006Co-Authors: Atsushi Sugimoto, Takahide Fukuyama, Yukihito Sumino, Makoto Takagi, Ilhyong RyuAbstract:The Barton Reaction (nitrite photolysis) of a steroidal substrate 1, to give 2, a key intermediate for the synthesis of an endothelin receptor antagonist, was successfully carried out in a continuous microflow system using a pyrex glass-covered stainless-steel microreactor having a microchannel (Type A: 1000 μm width, 107 μm depth, 2.2 m length). We found that a 15 W black light (peak wavelength: 352 nm) as the light source, suffices for the Barton Reaction, creating a compact photo-micro Reaction system. Multi-gram scale production was attained using two serially connected, multi-lane microreactors (Type B).
Krzysztof Bobrowski - One of the best experts on this subject based on the ideXlab platform.
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Intramolecular hydrogen transfer as the key step in the dissociation of hydroxyl radical adducts of (alkylthio)ethanol derivatives
Journal of the American Chemical Society, 1993Co-Authors: Christian Schöneich, Krzysztof BobrowskiAbstract:The Reaction of the hydroxyl radical with dimethyl sulfide (DMS), 2-(methylthio)ethanol (2-MTE), 2,2'-dihydroxydiethyl sulfide (2,2'-DHE), and 3,3'-dihydroxydipropyl sulfide (3,3'-DHP) has been investigated in H[sub 2]O and D[sub 2]O. As an initial step hydroxyl radicals add to the sulfur moiety. These hydroxyl radical adducts subsequently decay via a thioether concentration-dependent and a thioether concentration-independent pathway. The hydroxyl radical adduct of DMS dissociates into a sulfur radical cation and HO[minus] in the thioether concentration-independent pathway (k[sub H]/k[sub D] = 2.09), whereas a rate-limiting proton transfer from water operates in the thioether concentration-dependent mechanism (k[sub H]/k[sub D] = 5.40), as deduced from the measured solvent kinetic isotope effects. In contrast the hydroxyl radical adducts of 2-MTE and 2,2'-DHE decompose via elimination of water, formed through a rapid intramolecular hydrogen transfer from the adjacent hydroxyl groups. This mechanism leads to the formation of (alkylthio)ethoxy radicals. The latter undergo [alpha],[beta]-fragmentation into formaldehyde and [alpha]-thioether radicals as well as hydrogen abstraction from a [delta]-methylene group, analogous to a hydrogen transfer in the Barton Reaction, leading to [alpha]-thioether radicals. 37 refs., 5 figs., 2 tabs.
Carolyn B. Knobler - One of the best experts on this subject based on the ideXlab platform.
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Adaptation of the Barton Reaction to Carborane Chemistry: The Synthesis and Reactivity of 2‐Hydroxyimino‐1‐hydroxymethylnona‐B‐methyl‐1,12‐dicarba‐closo‐dodecaborane(12)
Angewandte Chemie (International ed. in English), 1998Co-Authors: Axel Herzog, Carolyn B. Knobler, M. Frederick HawthorneAbstract:Just one of the ten methyl groups of deca-B-methyl-1,12-dicarba-closo-dodecarborane(12) (1) is selectively functionalized in a Reaction sequence in which photolysis of a nitrite of 1 is the key step. Reduction of the resulting aldoxime with LiAlH4 generates, by way of the first Beckmann rearrangement of a boron-substituted oxime, the methylamino alcohol 2.
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adaptation of the Barton Reaction to carborane chemistry the synthesis and reactivity of 2 hydroxyimino 1 hydroxymethylnona b methyl 1 12 dicarba closo dodecaborane 12
Angewandte Chemie, 1998Co-Authors: Axel Herzog, Carolyn B. Knobler, Frederick M HawthorneAbstract:Just one of the ten methyl groups of deca-B-methyl-1,12-dicarba-closo-dodecarborane(12) (1) is selectively functionalized in a Reaction sequence in which photolysis of a nitrite of 1 is the key step. Reduction of the resulting aldoxime with LiAlH4 generates, by way of the first Beckmann rearrangement of a boron-substituted oxime, the methylamino alcohol 2.
