Xn:Harmful;
83-33-0Relevant articles and documents
Photoinduced Double Addition of Acetylene to 3-Oxocyclopent-1-ene-1-carbonitrile or 3-Oxocyclopent-1-enyl Acetate Leading to 2,3-Dihydro-1H-inden-1-one and Other Rearranged Products
Cavazza, Marino,Guella, Graziano,Pietra, Francesco
, p. 1608 - 1615 (1988)
UV Irradiation of 3-oxocyclopent-1-enyl acetate (17) and acetylene in MeCN at 0 deg C gives, besides the product of normal enone-alkyne cycloaddition (cis-4-oxobicyclohept-6-en-1-yl acetate, 18) and its product of oxa-di-?-methane rearrangement (5-oxotricyclo2,7>hept-2-yl acetate, 19), unexpected products of further addition of a molar equivalent of acetylene.These are indanone (= 2,3-dihydro-1H-inden-1-one, 16), in 21percent yield, cis-1-cisoid-1,2-cis-2- (20) and cis-1-transoid-1,2-cis-2,7-oxotricyclo2,5>non-3-en-1-yl acetate (21), 4-oxo-7-'exo'-vinyltricyclo2,6>hept-2-yl acetate (22), cis-4-oxo-6 -'endo'- (23) and cis-4-oxo-6-'exo'-vinylbicyclohept-1-yl acetate (24), and cis-4-oxo-7-'exo'-vinylbicyclohept-1-yl acetate (25).At least in part, indanone must be formed via intermediates 20 and 21.In fact, on heating a 9:1 mixture 20/21, indanone is obtained quantitatively.With 3-oxocyclopent-1-ene-1-carbonitrile (15) in place of 17, indanone is formed in lower (8percent) yield besides much tars.
Solid state asymmetric synthesis of chiral crystals of 5- and 7-membered ring ketones
Xu, Xianzhu,Wang, Peng,Xia, Wujiong,Yang, Chao
, p. 150 - 151 (2008)
The results of absolute asymmetric photochemical studies on 5- and 7-membered spiroketones in the solid state are described. Photolysis of 7-membered spiroketone undergoing a Norrish type II cyclisation reaction gives enantioselectivity excesses up to 93%. Irradiation of 5-membered spiroketone afforded a racemic product. The results are rationalised by the X-ray crystallographic method.
Covalent Linkage of an R-ω-Transaminase to a d-Amino Acid Oxidase through Protein Splicing to Enhance Enzymatic Catalysis of Transamination
Du, Kun,Li, Rong,Zhang, Dongrui,Feng, Wei
, p. 701 - 709 (2019)
R-ω-Transaminases (RTAs) catalyse the conversion of R-configured amines [e.g., (R)-1-phenylethylamine] into the corresponding ketones (e.g., acetophenone), by transferring an amino group from an amino donor [e.g., (R)-1-phenylethylamine] onto an amino acceptor (e.g., pyruvate), resulting in a co-product (e.g., d-alanine). d-Alanine can be deaminated back to pyruvate by d-amino acid oxidase (DAAOs). Here, through in vivo subunit splicing, the N terminus of an RTA subunit (RTAS) was specifically ligated to the C terminus of a DAAO subunit (DAAOS) through native peptide bonds (RTA&DAAO). RTAS is in close proximity to DAAOS, at a molecular-scale distance. Thus the transfer of pyruvate and d-alanine between RTA and DAAO can be directional and efficient. Pyruvate→d-alanine→pyruvate cycles are efficiently formed, thus promoting the forward transamination reaction. In a different, in vitro noncovalent approach, based on coiled-coil association, the RTAS N terminus was specifically associated with the DAAOS C terminus (RTA#DAAO). In addition, the two mixed individual enzymes (RTA+DAAO) were also studied. RTA&DAAO has a shorter distance between the paired subunits (RTAS–DAAOS) than RTA#DAAO, and the number of the paired subunits is higher than in the case of RTA#DAAO, whereas RTA+DAAO cannot form the paired subunits. RTA&DAAO exhibited a transamination catalysis efficiency higher than that of RTA#DAAO and much higher than that of RTA+DAAO.
Improved synthetic route to methyl 1-fluoroindan-1-carboxylate (FICA Me ester) and 4-methyl derivatives
Koyanagi, Jyunichi,Kamei, Tomoyo,Ishizaki, Miyuki,Nakamura, Hiroshi,Takahashi, Tamiko
, p. 816 - 819 (2014)
An improved synthetic route has been developed for the preparation of methyl 1-fluoroindan-1-carboxylate (FICA Me ester) from 1-indanone. Methyl 4-methyl-1-fluoroindan-1-carboxylate (4-Me-FICA Me ester) was also prepared following the same procedure.
Catalytic Aerobic Oxidation of Alkenes with Ferric Boroperoxo Porphyrin Complex; Reduction of Oxygen by Iron Porphyrin
Kimura, Kento,Kurahashi, Takuya,Matsubara, Seijiro,Murano, Shunpei
supporting information, p. 2493 - 2497 (2021/12/29)
We herein describe the development of a mild and selective catalytic aerobic oxidation process of olefins. This catalytic aerobic oxidation reaction was designed based on experimental and spectroscopic evidence assessing the reduction of atmospheric oxygen using a ferric porphyrin complex and pinacolborane to form a ferric boroperoxo porphyrin complex as an oxidizing species. The ferric boroperoxo porphyrin complex can be utilized as an in-situ generated intermediate in the catalytic aerobic oxidation of alkenes under ambient conditions to form oxidation products that differ from those obtained using previously reported ferric porphyrin catalysis. Moreover, the mild reaction conditions allow chemoselective oxidation to be achieved.
Electrochemical Difunctionalization of Styrenes via Chemoselective Oxo-Azidation or Oxo-Hydroxyphthalimidation
Jiang, Haobin,Wang, Feng,Ye, Zenghui,Zhang, Fengzhi,Zhu, Rongjin
supporting information, p. 8240 - 8245 (2021/11/17)
Atom- and step-economic oxo-azidation and oxo-hydroxyphthalimidation of styrenes have been developed under mild electrolytic conditions, respectively. Various valuable alpha-azido or hydroxyphthalimide aromatic ketones were synthesized efficiently from readily available styrenes, azides, and N-hydroxyphthalimides. Mechanism studies show that two different pathways involved in these two transformations.
Oxidative Cleavage of Alkenes by O2with a Non-Heme Manganese Catalyst
Bennett, Elliot L.,Brookfield, Adam,Guan, Renpeng,Huang, Zhiliang,Mcinnes, Eric J. L.,Robertson, Craig M.,Shanmugam, Muralidharan,Xiao, Jianliang
supporting information, p. 10005 - 10013 (2021/07/19)
The oxidative cleavage of C═C double bonds with molecular oxygen to produce carbonyl compounds is an important transformation in chemical and pharmaceutical synthesis. In nature, enzymes containing the first-row transition metals, particularly heme and non-heme iron-dependent enzymes, readily activate O2 and oxidatively cleave C═C bonds with exquisite precision under ambient conditions. The reaction remains challenging for synthetic chemists, however. There are only a small number of known synthetic metal catalysts that allow for the oxidative cleavage of alkenes at an atmospheric pressure of O2, with very few known to catalyze the cleavage of nonactivated alkenes. In this work, we describe a light-driven, Mn-catalyzed protocol for the selective oxidation of alkenes to carbonyls under 1 atm of O2. For the first time, aromatic as well as various nonactivated aliphatic alkenes could be oxidized to afford ketones and aldehydes under clean, mild conditions with a first row, biorelevant metal catalyst. Moreover, the protocol shows a very good functional group tolerance. Mechanistic investigation suggests that Mn-oxo species, including an asymmetric, mixed-valent bis(μ-oxo)-Mn(III,IV) complex, are involved in the oxidation, and the solvent methanol participates in O2 activation that leads to the formation of the oxo species.
Simultaneous Preparation of (S)-2-Aminobutane and d -Alanine or d -Homoalanine via Biocatalytic Transamination at High Substrate Concentration
Li, Jianjiong,Wang, Yingang,Wu, Qiaqing,Yao, Peiyuan,Yu, Shanshan,Zhu, Dunming
supporting information, (2022/03/01)
(S)-2-Aminobutane, d-alanine, and d-homoalanine are important intermediates for the production of various active pharmaceutical ingredients and food additives. The preparation of these small chiral amine or amino acids with high water solubility still demands searching for efficient methods. In this work, we identified an ω-transaminase (ω-TA) from Sinirhodobacter hungdaonensis (ShdTA) that catalyzed the kinetic resolution of racemic 2-aminobutane at a concentration of 800 mM using pyruvate as the amino acceptor, leading to the simultaneous isolation of enantiopure (S)-2-aminobutane and d-alanine in 46% and 90% yield, respectively. In addition, (S)-2-aminobutane (98% ee) and d-homoalanine (99% ee) were isolated in 45% and 93% yield, respectively, in the kinetic resolution of racemic 2-aminobutane at a concentration of 400 mM coupled with deamination of l-threonine by threonine deaminase. We thus developed a biocatalytic process for the practical synthesis of these valuable small chiral amine and d-amino acids.
METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
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Paragraph 0053-0059, (2021/03/19)
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method comprises the following step: (A) providing a compound (I) with an unsaturated double bond, a reagent with trifluoromethyl, and a catalyst; wherein the catalyst is represented by the following formula (II): M(O)mL1yL2z (II); wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and (B) mixing the compound with an unsaturated double bond and the reagent with a trifluoromethyl to perform an oxidation of the compound with the unsaturated double bond by using the catalyst at air or an oxygen condition to get a compound presented as formula (III):
Method for oxidative cracking of compound containing unsaturated double bonds
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Paragraph 0108-0120; 0173-0175; 0194-0196, (2021/07/09)
The invention relates to a method for oxidative cracking of a compound containing unsaturated double bonds. The method comprises the following steps: (A) providing a compound (I) containing unsaturated double bonds, a trifluoromethyl-containing reagent and a catalyst, wherein the catalyst is shown as a formula (II): M(O)mL1yL2z (II), M, L1, L2, m, y, z, R1, R2 and R3 being defined in the specification; and (B) mixing the compound containing the unsaturated double bonds and the trifluoromethyl-containing reagent, and performing an oxidative cracking reaction on the compound containing the unsaturated double bonds in the presence of air or oxygen by using the catalyst to obtain a compound represented by formula (III),.
