1257415-72-7Relevant academic research and scientific papers
Catalytic asymmetric synthesis of the common amino acid component in the biosynthesis of tetrahydroisoquinoline alkaloids
Tanifuji, Ryo,Oguri, Hiroki,Koketsu, Kento,Yoshinaga, Yuki,Minami, Atsushi,Oikawa, Hideaki
, p. 623 - 626 (2016)
Biosynthetic assembly lines of tetrahydroisoquinoline alkaloids employ the tyrosine derivative, (S)-2-amino-3-(3-hydroxy-4-methoxy-5-methylphenyl)propanoic acid, as a common amino acid building block. A catalytic asymmetric synthetic route to the common amino acid component has been developed by making use of Maruoka's chiral phase transfer alkylation of a glycine derivative with the requisite benzyl bromide.
Synthesis of methylated quercetin analogues for enhancement of radical-scavenging activity
Imai, Kohei,Nakanishi, Ikuo,Ohkubo, Kei,Ohba, Yusuke,Arai, Takuya,Mizuno, Mirei,Fukuzumi, Shunichi,Matsumoto, Ken-ichiro,Fukuhara, Kiyoshi
, p. 17968 - 17979 (2017/03/31)
Three quercetin derivatives with enhanced radical-scavenging activity were designed and synthesised. Because the radical-scavenging reaction of quercetin is known to proceed via an electron transfer from quercetin to radicals, producing the corresponding quercetin radical cation intermediate, the introduction of electron-donating groups into the quercetin molecule is expected to enhance its radical-scavenging activity. Thus, methyl groups were introduced into the catechol moiety in the quercetin molecule at either the 2′- or 5′-position, or both. All three quercetin analogues were found to exhibit higher radical-scavenging activity than the parent quercetin. The activity of 5′-methylquercetin is the highest among the three analogues. The optimised structure of 5′-methylquercetin calculated by density functional theory demonstrated a coplanar structure between the 4H-curomen (AC rings) and catechol (B ring) moieties, while dimethylquercetin and 2′-methylquercetin have a twisted structure between the AC and B rings. These results demonstrate that the highest radical-scavenging activity of 5′-methylquercetin is due to the stabilisation of the radical cation intermediate by the electron-donating effect of the methyl group as well as by the planar structure of the molecule.
Cu(OAc)2-catalyzed remote benzylic C(sp3)-H oxyfunctionalization for C=O formation directed by the hindered para-hydroxyl group with ambient air as the terminal oxidant under ligand- and additive-free conditions
Jiang, Jian-An,Chen, Cheng,Huang, Jian-Gang,Liu, Hong-Wei,Cao, Song,Ji, Ya-Fei
supporting information, p. 1248 - 1254 (2014/03/21)
A hindered para-hydroxyl group-directed remote benzylic C(sp3)-H oxyfunctionalization has been developed for the straightforward transformation of 2,6-disubstituted 4-cresols, 4-alkylphenols, 4-hydroxybenzyl alcohols and 4-hydroxybenzyl alkyl ethers into various aromatic carbonyl compounds. The ligand- and additive-free Cu(OAc)2-catalyzed atmospheric oxidation mediated by ethylene glycol unlocks a facile, atom-economical, and environmentally benign C=O formation for the functionalization of primary and secondary benzyl groups. Due to the pharmaceutical importance of 4-hydroxybenzaldehydes and 4-hydroxyphenones, the methodology is expected to be of significant value for both fundamental research and practical applications.
Environmentally friendly and highly efficient Co(OAc)2-catalyzed aerobic oxidation to access 2,6-di-electron-donating group substituted 4-hydroxybenzaldehydes
Jiang, Jian-An,Du, Jia-Lei,Zhang, Zhong-Nan,Zhai, Jiao-Jiao,Ji, Ya-Fei
, p. 1430 - 1440 (2016/09/23)
A highly efficient and green aerobic oxidation has been developed for selectively preparing a series of valuable 2,6-dialkyl-, dialkoxyl-, and alkoxylalkyl-substituted 4-hydroxybenzaldehydes from corresponding 4-cresols in good to excellent yields, using a catalytic system of Co(OAc)24H2O (1.0 mol%)-NaOH (1.0 equiv)-O2(1.0 atm) in aqueous ethylene glycol (EG/H2O = 20/1, v/v) at 50 °C. Furthermore, a plausible mechanism was proposed for the direct oxyfunctionalization of the aromatic methyl group into the aldehyde group.
Synthesis of (±)-phthalascidin 650 analogue: New synthetic route to (±)-phthalascidin 622
Razafindrabe, Christian R.,Aubry, Sylvain,Bourdon, Benjamin,Andriantsiferana, Marta,Pellet-Rostaing, Stéphane,Lemaire, Marc
scheme or table, p. 9061 - 9066 (2011/01/04)
A synthesis of functionalized phenolic α-amino-alcohol (±)-13 as synthetic precursor of the catechol tetrahydroisoquinoline structure of phthalascidin 650 is disclosed. Starting from 3-methylcatechol 5, eight steps of synthesis give rise to the synthesis of phenolic α-amino-alcohol (±)-13 in 27% overall yield. This synthetic strategy involves the elaboration of fully functionalized aromatic aldehyde 8 and its transformation into a phenolic α-amino-alcohol (±)-13, through a Knoevenagel condensation, simultaneous reduction of nitroketene and ester functions and hydrogenolysis of the benzyl protecting group. The pentacycle (±)-18 was obtained after four additional steps. The Pictet-Spengler cyclisation between the phenolic α-amino-alcohol (±)-13 and N-protected α-amino-aldehyde 4 allowed to obtain (1,3′)-bis- tetrahydroisoquinoline 14 with N-methylated and N-Fmoc removed. The last step was a Swern oxidation for allowing an intramolecular condensation.
Synthesis of (±)-phthalascidin 622
Christian, R. Razafindrabe,Sylvain, Aubry,Benjamin, Bourdon,Marta, Andriantsiferana,Stephane, Pellet-Rostaing,Marc, Lemaire
experimental part, p. 1888 - 1898 (2011/02/26)
A synthesis of functionalized phenolic α-amino-alcohols (±)-8 and (±)-16 as synthetic precursors of the catechol tetrahydroisoquinoline structure of phthalascidin 650 was disclosed. (±)-8 was prepared in 5 steps from the commercially available sesamol. Starting from 3-methyl catechol 5, 8 steps gave rise to the synthesis of phenolic α-amino-alcohol (±)-16 in 27% overall yield. This synthetic strategy involved the elaboration of fully functionalized aromatic aldehyde 13 and its transformation into a phenolic α-amino-alcohol (±)-16, through a Knoevenagel condensation, simultaneous reduction of nitroketene and ester functions, and hydrogenolysis of the benzyl protecting group. The pentacycle (±)-4 was obtained after 4 additional steps. The Pictet-Spengler cyclisation between the phenolic α-amino-alcohol (±)-16 and the N-protected α-amino-aldehyde 4 allowed to obtain (1,3′)-bis- tetrahydroisoquinoline 17 with N-methylated and N-Fmoc removed. The last step was a Swern oxidation allowing the expected intramolecular condensation.
