24880-43-1Relevant articles and documents
Palladium-catalyzed asymmetric direct intermolecular allylation of α-aryl cyclic vinylogous esters: Divergent synthesis of (+)-oxomaritidine and (?)-mesembrine
Wang, Wei,Dai, Jun,Yang, Qiqiong,Deng, Yu-Hua,Peng, Fangzhi,Shao, Zhihui
, p. 920 - 924 (2021/02/16)
We demonstrate that α-aryl cyclic vinylogous esters are competent substrates in the direct intermolecular Pd-catalyzed asymmetric allylic alkylation, enabling a straightforward enantioselective synthesis of 6-allyl-6-aryl-3-ethoxycyclohex-2-en-1-ones, common motifs embedded in numerous structurally diverse natural products. As an initial demonstration of the utility of this protocol, the first catalytic enantioselective total synthesis of (+)-oxomaritidine and an improved five-step catalytic enantioselective synthesis of (?)-mesembrine have been completed divergently.
A Concise Total Synthesis of (-)-Mesembrine
Wang, Lu-Ning,Cui, Qi,Yu, Zhi-Xiang
, p. 10165 - 10171 (2016/11/17)
A concise total synthesis of mesembrine (four steps from known compound) was achieved both racemically and asymmetrically. Two key reactions were used here. One is the Rh(I)-catalyzed [5 + 1] cycloaddition of vinylcyclopropane 3c and CO. The other one is Buchwald's Pd-catalyzed coupling reaction that coupled β,γ-cyclohexenone 2c with aryl bromide 5 (using dppe ligand for racemic or (S)-Antphos ligand for asymmetric synthesis) to give γ,γ-disubstituted α,β-cyclohexenone 1c. Finally, aza-Michael addition converted 1c to mesembrine.
Highly chemoselective aerobic oxidation of amino alcohols into amino carbonyl compounds
Sasano, Yusuke,Nagasawa, Shota,Yamazaki, Mai,Shibuya, Masatoshi,Park, Jaiwook,Iwabuchi, Yoshiharu
supporting information, p. 3236 - 3240 (2014/04/03)
The direct oxidation of unprotected amino alcohols to their corresponding amino carbonyl compounds has often posed serious challenges in organic synthesis and has constrained chemists to adopting an indirect route, such as a protection/deprotection strategy, to attain their goal. Described herein is a highly chemoselective aerobic oxidation of unprotected amino alcohols to their amino carbonyl compounds in which 2-azaadamantane N-oxyl (AZADO)/copper catalysis is used. The catalytic system developed leads to the alcohol-selective oxidation of various unprotected amino alcohols, carrying a primary, secondary, or tertiary amino group, in good to high yield at ambient temperature with exposure to air, thus offering flexibility in the synthesis of nitrogen-containing compounds. Strong as an ox: The highly chemoselective aerobic oxidation of unprotected amino alcohols to their corresponding amino carbonyl compounds has been achieved by using 2-azaadamantane N-oxyl (AZADO)/copper catalysis. This catalytic system oxidizes not only alcohols with tertiary amino groups but also those with secondary and primary amines in good to high yield at ambient temperature in air. bpy=2,2-bipyridyl, DMAP=4-(N,N-dimethylamino)pyridine.
Consecutive sigmatropic rearrangements in the enantioselective total synthesis of (-)-joubertinamine and (-)-mesembrine
Ilardi, Elizabeth A.,Isaacman, Michael J.,Qin, Ying-chuan,Shelly, Sommer A.,Zakarian, Armen
experimental part, p. 3261 - 3269 (2009/08/15)
Joubertinamine and mesembrine are two related alkaloids isolated from Sceletium plants. From the perspective of chemical synthesis, the major challenge posed by joubertinamine and mesembrine is undoubtedly the construction of the benzylic quaternary stere
Opening of aryl-substituted epoxides to form quaternary stereogenic centers: Synthesis of (-)-mesembrine
Taber, Douglass F.,He, Yigang
, p. 7711 - 7714 (2007/10/03)
Cycloalkanones are easily converted into aryl-substituted cyclic alkenes by the addition of an aryl Grignard reagent followed by dehydration. These alkenes are good substrates for asymmetric epoxidation. We have found that the addition of allylic and benzylic Grignard reagents can occur preferentially at the benzylic position of the derived epoxides to give the quaternary stereogenic center. This approach led to a short synthesis of the nanomolar serotonin re-uptake inhibitor (-)-mesembrine.
Substituted urea-octatydroindols as antagonists of melanin concentrating hormone receptor 1 (MCH1R)
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Page/Page column 25-26, (2010/02/11)
The invention relates to compounds of the general formula (I) wherein R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, Ar, and X are as defined in the description, or a pharmaceutically acceptable salt, hydrates, geometrical isomers, racemates, tautomers, optical isomers, N-oxides and prodrug forms thereof. The compounds may be used for the treatment or prophylaxis of disorders related to the MCH1R receptor and for modulation of appetite. The invention also relates to such use as well as to pharmaceutical formulations comprising a compound of formula (I).
SUBSTITUTED UREA-OCTAHYDROINDOLS AS ANTAGONISTS OF MELANIN CONCENTRATING HORMONE RECEPTOR 1 (MCH1R)
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Page/Page column 18-19, (2010/02/11)
The invention relates to compounds of the general formula (I). (I) wherein R1, R2, R3, R4, R5, R6, R7, R8, and X are as defined in the description, or pharmaceutically acceptable salts, hydrates, geometrical isomers, racemates, tautomers, optical isomers, N-oxides and prodrug forms thereof. The compounds may be used for the treatment or prophylaxis of disorders related to the MCH1R receptor and for modulation of appetite. The invention also relates to such use as well as to pharmaceutical formulations comprising a compound of formula (I).
Enantioselective construction of cyclic quaternary centers: (-)-mesembrine
Taber,Neubert
, p. 143 - 147 (2007/10/03)
The preparation of the crystalline amide 2 is reported. Conjugate addition to 2 proceeded with the expected high diastereocontrol to give 3. This set the stage for subsequent intramolecular alkylidene C-H insertion to give, after ozonolysis and aldol condensation, (-)-mesembrine 1. Amide 2 should be a useful chiron for the enantioselective construction of cyclic quaternary centers.
Asymmetric synthesis of sceletium alkaloids: (-)-Mesembrine, (+)- sceletium a-4, (+)-tortuosamine and (+)-N-formyltortuosamine
Yamada, Osamu,Ogasawara, Kunio
, p. 7747 - 7750 (2007/10/03)
Three procedures for the transformation of achiral 1-(3,4- dimethoxyphenyl)cyclohexene into enantiomerically pure 2-(3,4- dimethoxyphenyl)cyclohex-2-en-1-o1 have been established at first. Utilizing the (-)-cyclohexenol thus obtained, the four titled Sceletium alkaloids have been synthesized in the natural enantiomeric forms.
A concise synthesis of (-)-mesembrine
Dalko, Peter I.,Brun, Virginie,Langlois, Yves
, p. 8979 - 8982 (2007/10/03)
(-)-Mesembrine 11 was synthesized in 7 steps, in 19.4% overall yield and with ee>95%. The key step of the sequence is a stereoselective alkylation reaction of dianion derived from C2 symmetric imidazolines allowing efficient formation of quaternary benzylic center. Chiral auxiliaries derived from (S,S)-1,2-diamino-1,2-diphenylethane 1a and (S,S)-1,2-diaminocyclohexane 1b were compared. This synthesis provided unambiguous correlation of the newly formed stereocenter.