133473-26-4Relevant academic research and scientific papers
Photodemethylation of Methoxy-Substituted 9,10-Anthraquinones in Methanol
Blankespoor, Ronald L.,Hsung, Richard,Schutt, David L.
, p. 2877 - 2878 (1988)
Irradiation of methoxy-substituted 9,10-anthraquinones with visible or ultraviolet light results in a demethylation reaction involving free radical intermediates.
(±)-cis-4a-alkyl-1,3,4,4a,9,9a-hexahydro-2H-carbazol-2-ones by domino nitro reduction-aza-Michael addition to enones
Barrios-Perez, Carlos,Bunce, Richard A.,Embrey, Samuel J.
, (2022/01/11)
A domino nitro reduction-aza-Michael addition sequence has been investigated for α,β-unsaturated ketones and compared with the analogous reaction for conjugated esters. As expected, six-membered ring closures of ketones did not proceed as well as for esters (85%) due to the greater inherent reactivity of the ketones. This problem was minimized by performing the cyclization at lower temperature for a shorter time. The process has been extended to a synthesis of (±)-cis-4a-alkyl-1,3,4,4a,9,9a-hexahydro-2H-carbazol-2-ones with good yields (65%–86%). While the rigidity of the system and closure of the smaller five-membered ring created some strain in the products, yields were acceptable. The cis ring junction resulted from axial attack to give a more stable chair-like enol that tautomerized to the target heterocycle.
CoPd Nanoalloys with Metal–Organic Framework as Template for Both N-Doped Carbon and Cobalt Precursor: Efficient and Robust Catalysts for Hydrogenation Reactions
Zhu, Jie,Xu, Deng,Ding, Lu-jia,Wang, Peng-cheng
, p. 2707 - 2716 (2021/01/21)
In this work, a series of metal–organic framework (MOF)-derived CoPd nanoalloys have been prepared. The nanocatalysts exhibited excellent activities in the hydrogenation of nitroarenes and alkenes in green solvent (ethanol/water) under mild conditions (H2 balloon, room temperature). Using ZIF-67 as template for both carbon matrix and cobalt precursor coating with a mesoporous SiO2 layer, the catalyst CoPd/NC@SiO2 was smoothly constructed. Catalytic results revealed a synergistic effect between Co and Pd components in the hydrogenation process due to the enhanced electron density. The mesoporous SiO2 shell effectively prevented the sintering of hollow carbon and metal NPs at high temperature, furnishing the well-dispersed nanoalloy catalysts and better catalytic performance. Moreover, the catalyst was durable and showed negligible activity decay in recycling and scale-up experiments, providing a mild and highly efficient way to access amines and arenes.
Synthesis of indolines via a SmI2 promoted domino nitro reduction-intramolecular aza-Michael reaction
Ramos, Josierika A. Ferreira,Araújo, Carolina S.,Nagem, Tanus J.,Taylor, Jason G.
, p. 54 - 58 (2015/01/30)
A simple and straightforward synthesis of substituted indolines based on a domino nitro reduction intramolecular aza-Michael reaction is described. The reaction employs Samarium diiodide under mild conditions for the addition of dibromoacetic acid to substituted 2-(2-nitrophenyl) acetaldehyde derivatives and their subsequent cyclization upon nitro group reduction to provide corresponding indoline heterocycles in good yields. This "one pot" strategy also permitted the expeditious synthesis of a 1,2,3,4-tetrahydroquinoline, whereas the seven-membered 2,3,4,5-tetrahydrobenzoazepines compounds were not formed under these reaction conditions.
Process for Synthesis of Chiral 3-Substituted Tetrahydroquinoline Derivatives
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, (2015/02/19)
The present invention relates to novel and concise process for the construction of chiral 3-substituted tetrahyroquinoline derivatives based on proline catalyzed asymmetric α-functionalization of aldehyde, followed by in situ reductive cyclization of nitro group under catalytic hydrogenation condition with high optical purities. Further the invention relates to conversion of derived chiral 3-substituted tetrahydroquinoline derivatives into therapeutic agents namely (?)-sumanirole (96% ee) and 1-[(S)-3-(di-methylamino)-3,4-dihydro-6,7-dimethoxy-quinolin-1(2H)-yl]propanone[(S)-903] (92% ee).
How phenyl makes a difference: Mechanistic insights into the ruthenium(ii)-catalysed isomerisation of allylic alcohols
Manzini, Simone,Poater, Albert,Nelson, David J.,Cavallo, Luigi,Nolan, Steven P.
, p. 180 - 188 (2014/01/06)
[RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols.
A PROCESS FOR SYNTHESIS OF CHIRAL 3-SUBSTITUTED TETRAHYDROQUINOLINE DERIVATIVES
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, (2013/10/08)
The present invention relates to novel and concise process for the construction of chiral 3-substituted tetrahydroquinoline derivatives based on proline catalyzed asymmetric α-functionalization of aldehyde, followed by in situ reductive cyclization of nitro group under catalytic hydrogenation condition with high optical purities. Further the invention relates to conversion of derived chiral 3-substituted tetrahydroquinoline derivatives into therapeutic agents namely (-)-sumanirole (96% ee) and 1-[(S)-3-(dimethylamino)-3,4-dihydro-6,7-dimethoxy-quinolin-1(2H)-yl]propanone[(S)-903] (92% ee).
Proline catalyzed sequential α-aminooxylation or -amination/reductive cyclization of o-nitrohydrocinnamaldehydes: A high yield synthesis of chiral 3-substituted tetrahydroquinolines
Rawat, Varun,Kumar, B. Senthil,Sudalai, Arumugam
supporting information, p. 3608 - 3611 (2013/06/26)
A new sequential organocatalytic method for the synthesis of chiral 3-substituted (X = OH, NH2) tetrahydroquinoline derivatives (THQs) [ee up to 99%, yield up to 87%] based on α-aminooxylation or -amination followed by reductive cyclization of o-nitrohydrocinnamaldehydes has been described. This methodology has been efficiently demonstrated in the synthesis of two important bioactive molecules namely (-)-sumanirole (96% ee) and 1-[(S)-3-(dimethylamino)-3,4-dihydro-6,7-dimethoxy-quinolin-1(2H)-yl]propanone (92% ee). The Royal Society of Chemistry 2013.
Conjugate reduction of α,β-unsaturated aldehydes with rhodium(bis-oxazolinylphenyl) catalysts
Kanazawa, Yoshinori,Nishiyama, Hisao
, p. 3343 - 3345 (2008/09/18)
α,β-Unsaturated aldehydes were selectively reduced using rhodium(bisoxazolinylphenyl) complexes to give exclusive 1,4-selectivity in the combination of alkoxyhydrosilanes. Georg Thieme Verlag Stuttgart.
METHOD FOR HYDROGENATION OF α,β-UNSATURATED CARBONYL COMPOUNDS
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Page/Page column 10-11, (2008/06/13)
A method for the chemoselective hydrogenation of a,? unsaturated carbonyl compounds is disclosed, in which compounds of general formula (I), where R1 = H, branched, unbranched, saturated or unsaturated 1-30C hydrocarbon group which may have suitable substituents and the hydrocarbon group may have one or more heteroatoms in the chain, aryl or heteroaryl group which can have suitable substituents, R2, R3 and R4 independently = H, F, Cl, Br, I, OH, CN, NO2, NO, SO2, SO3, amino, mono- and di-(C1-C24) alkyl substituted amino, mono- and di-(C5-C20) aryl substituted amino, imino, phosphono, phosphonato, phosphinato, phospho, phosphino, a branched, unbranched, saturated or unsaturated 1-30C hydrocarbon group which may have suitable substituents and the hydrocarbon group may have one or more heteroatoms in the chain, aryl or heteroaryl group which can have suitable substituents, each of R2, R3 and R4 can form a 5- or 6-membered ring or annelated 5-and/or 6-membered rings which can be aromatic, alicyclic, heteroaromatic or heteroalicyclic and have up to 4 substituents, are reacted with a hybrid donor to form a compound of general formula (II) in which R1, R2, R3 and R4 are as above. Said method permits the selective hydrogenation of a,? unsaturated aldehydes and ketones without the use of metal catalysts.
