The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Kazuhiro Yoshida - One of the best experts on this subject based on the ideXlab platform.
-
reactive barium promoted benzylation of diaryl Azo Compounds
Synlett, 2015Co-Authors: Akira Yanagisawa, Toshiki Sawae, Seiya Yamafuji, Toshihiko Heima, Kazuhiro YoshidaAbstract:The Barbier-type benzylation of Azo Compounds with benzylic chlorides was achieved by using reactive barium as the promoter. Various benzylic hydrazines were synthesized from the corresponding benzylic chlorides. The thus-obtained benzylic hydrazines were further efficiently converted into benzylic amines by reductive N–N bond cleavage.
-
α selective allylation of Azo Compounds using allylic barium reagents
Synlett, 2013Co-Authors: Akira Yanagisawa, Takuya Jitsukawa, Kazuhiro YoshidaAbstract:The addition of allylic barium reagents to Azo Compounds was achieved with high α-regioselectivity. The double-bond geometry of allylic barium reagents was retained throughout the reaction at –78 °C and E- or Z-enriched allylic hydrazines were selectively obtained from the corresponding allylic barium reagents. An allylic hydrazine was efficiently converted into an allylic amine by reductive N–N bond cleavage.
-
Selective Propargylation of Azo Compounds with Barium Reagents
Synlett, 2010Co-Authors: Akira Yanagisawa, Takanori Koide, Kazuhiro YoshidaAbstract:A Barbier-type propargylation of Azo Compounds with γ-trialkylsilylated propargylic bromides has been achieved using reactive barium as a low-valent metal in THF. Corresponding propargylated hydrazines (α-adducts) were exclusively formed not only from Azobenzenes (diaryldiazenes) but also from dialkyl Azodicarboxylates. This method is also applicable to γ-alkylated or γ-phenylated propargylic bromides, providing the desired propargylated products only.
Shikai Tian - One of the best experts on this subject based on the ideXlab platform.
-
palladium catalyzed regioselective halogenation of aromatic Azo Compounds
ChemInform, 2013Co-Authors: Shikai TianAbstract:A wide range of different substituted diaryl-Azo Compounds can be brominated or iodinated with excellent ortho-selectivity under mild reaction conditions.
-
Palladium‐Catalyzed Regioselective Halogenation of Aromatic Azo Compounds.
ChemInform, 2013Co-Authors: Shikai TianAbstract:A wide range of different substituted diaryl-Azo Compounds can be brominated or iodinated with excellent ortho-selectivity under mild reaction conditions.
-
palladium catalyzed regioselective halogenation of aromatic Azo Compounds
Advanced Synthesis & Catalysis, 2013Co-Authors: Shikai TianAbstract:A highly regioselective halogenation reaction of symmetrical and unsymmetrical aromatic Azo Compounds has been developed at room temperature or at 50 °C. In the presence of 5 mol% palladium diacetate and 0.5 equiv. of p-toluenesulfonic acid, a range of symmetrical aromatic Azo Compounds smoothly undergo monobromination with N-bromosuccinimide to give the corresponding unsymmetrical aromatic Azo Compounds in good to excellent yields with >99:1 ortho-selectivity. This chemistry has been successfully extended to unsymmetrical aromatic Azo Compounds, whose electron-richer aryl groups prefer to be monobrominated. Moreover, replacing N-bromosuccinimide with N-iodosuccinimide in the reaction allows the synthesis of monoiodinated aromatic Azo Compounds with >99:1 regioselectivity.
Satoshi Minakata - One of the best experts on this subject based on the ideXlab platform.
-
oxidative dimerization of hetero aromatic amines utilizing t buoi leading to hetero aromatic Azo Compounds scope and mechanistic studies
Journal of Organic Chemistry, 2013Co-Authors: Sota Okumura, Youhei Takeda, Chunhsuan Lin, Satoshi MinakataAbstract:A straightforward synthetic method of both symmetric and unsymmetric aromatic Azo Compounds through an efficient and cross-selective oxidative dimerization of aromatic amines using tert-butyl hypoiodite (t-BuOI) under metal-free and mild conditions has been developed. This method was also found applicable to the synthesis of heteroaromatic Azo Compounds. The spectroscopic study indicates the involvement of N,N-diiodoanilines in the oxidative reaction as the key intermediate.
-
oxidative dimerization of aromatic amines using tbuoi entry to unsymmetric aromatic Azo Compounds
ChemInform, 2013Co-Authors: Youhei Takeda, Sota Okumura, Satoshi MinakataAbstract:Homo- and cross-dimerization of the aromatic and heteroaromatic amines is achieved using tBuOI, generated in situ, to afford symmetric and unsymmetric aromatic Azo Compounds in good yields.
-
oxidative dimerization of aromatic amines using tbuoi entry to unsymmetric aromatic Azo Compounds
Angewandte Chemie, 2012Co-Authors: Youhei Takeda, Sota Okumura, Satoshi MinakataAbstract:It's all the hype: An oxidative dimerization reaction of aromatic amines utilizing tert-butyl hypoiodite (tBuOI) under mild reaction conditions leads to aromatic Azo Compounds. The method allows access to unsymmetric aromatic Azo Compounds, which are difficult to prepare by conventional synthetic methods, in a selective manner.
Akira Yanagisawa - One of the best experts on this subject based on the ideXlab platform.
-
reactive barium promoted benzylation of diaryl Azo Compounds
Synlett, 2015Co-Authors: Akira Yanagisawa, Toshiki Sawae, Seiya Yamafuji, Toshihiko Heima, Kazuhiro YoshidaAbstract:The Barbier-type benzylation of Azo Compounds with benzylic chlorides was achieved by using reactive barium as the promoter. Various benzylic hydrazines were synthesized from the corresponding benzylic chlorides. The thus-obtained benzylic hydrazines were further efficiently converted into benzylic amines by reductive N–N bond cleavage.
-
α selective allylation of Azo Compounds using allylic barium reagents
Synlett, 2013Co-Authors: Akira Yanagisawa, Takuya Jitsukawa, Kazuhiro YoshidaAbstract:The addition of allylic barium reagents to Azo Compounds was achieved with high α-regioselectivity. The double-bond geometry of allylic barium reagents was retained throughout the reaction at –78 °C and E- or Z-enriched allylic hydrazines were selectively obtained from the corresponding allylic barium reagents. An allylic hydrazine was efficiently converted into an allylic amine by reductive N–N bond cleavage.
-
Selective Propargylation of Azo Compounds with Barium Reagents
Synlett, 2010Co-Authors: Akira Yanagisawa, Takanori Koide, Kazuhiro YoshidaAbstract:A Barbier-type propargylation of Azo Compounds with γ-trialkylsilylated propargylic bromides has been achieved using reactive barium as a low-valent metal in THF. Corresponding propargylated hydrazines (α-adducts) were exclusively formed not only from Azobenzenes (diaryldiazenes) but also from dialkyl Azodicarboxylates. This method is also applicable to γ-alkylated or γ-phenylated propargylic bromides, providing the desired propargylated products only.
Jochen Dipl Chem Dr Dauth - One of the best experts on this subject based on the ideXlab platform.
-
The photochemical decomposition of Azo Compounds (a spin trap study)
Journal of Photochemistry and Photobiology A: Chemistry, 1993Co-Authors: Andrej Staško, Katarina Szaboova, Vladimir Cholvad, Oskar Nuyken, Jochen Dipl Chem Dr DauthAbstract:Abstract The radical products formed in the photochemical decomposition of Azo Compounds (R 1 N 2 R 2 ) dissolved in various solvents were investigated. Nitrosodurene, 2-methyl-2-nitroso-propane and 5,5-dimethyl-1-pyrroline- N -oxide (DMPO) were used as spin traps. In the first group of Azo Compounds, in which R 1 was X-substituted phenyl and R 2 was SO 3 Na or SO 2 Ph, the spin adducts of R 1 and R 2 were observed. In the second group of Azo Compounds (R 1 = R 2 = R, where R was a tertiary-substituted carbon), the carbon-centred radicals R . were formed and trapped if irradiated in an argon atmosphere. When irradiated in air, the initially formed radicals R . were converted to oxygen-centred radicals (presumably peroxy or alkoxy) and trapped by DMPO; . OH radicals were also observed as further intermediates.
