- One-pot tandem route to fused indolizidines and quinolizidines: Application in the synthesis of alkaloids and bioactive compounds
-
Fused indolizidines and quinolizidines are important skeletons in a variety of natural products and pharmacologically important compounds. A one-pot tandem route from amide to fused indolizidines and quinolizidines is disclosed. This method is conducted in mild conditions and shows well tolerance of functional groups. It is also easy to be scaled up to gram scale and can be applied smoothly to the total synthesis of alkaloids such as (±)-crispine A, (±)-xylopinine, (±)-desbromoarborescidine A, (±)-harmicine and other bioactive substances.
- Song, Qiao,Liu, Yan,Cai, Linlin,Cao, Xinyu,Qian, Shan,Wang, Zhouyu
-
supporting information
p. 1713 - 1716
(2021/03/08)
-
- COMPOUNDS, COMPOSITIONS AND METHODS FOR TREATING NASH, NAFLD, AND OBESITY
-
The present technology relates to methods of treating NASH, NAFLD and/or obesity using compounds of Formulas I, II, III, IV, V, and/or VI. The methods include administering to a subject suffering from one or more of non-alcoholic steatohepatitis (NASH), non- alcoholic fatty liver disease (NAFLD) and/or obesity a therapeutically effective amount of such a compound
- -
-
Paragraph 00245; 00248
(2021/04/10)
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- Total Synthesis of (-)-Canadine, (-)-Rotundine, (-)-Sinactine, and (-)-Xylopinine Using a Last-Step Enantioselective Ir-Catalyzed Hydrogenation
-
A concise asymmetric total synthesis of a group of tetrahydroprotoberberine alkaloids, (-)-canadine, (-)-rotundine, (-)-sinactine, and (-)-xylopinine, has been accomplished in three steps from the commercially available corresponding disubstituted phenylethylamine and disubstituted benzaldehyde. Our synthesis toward these four alkaloids took advantage of the following strategy: In the first step, we achieved an efficient and sustainable synthesis of secondary amine hydrochlorides via a fully continuous flow; in the second step, we developed a Pictet-Spengler reaction/Friedel-Crafts hydroxyalkylation/dehydration cascade for the construction of the dihydroprotoberberine core structure (ABCD-ring); and in the last step, Ir-catalyzed enantioselective hydrogenation was employed for the introduction of the desired stereochemistry at the C-14 position in the tetrahydroprotoberberine alkaloids. This work significantly expedites the asymmetric synthesis of the entire tetrahydroprotoberberine alkaloid family as well as a more diverse set of structurally related non-natural analogues.
- Chen, Fener,Chen, Wenchang,Chen, Yu,Jiang, Meifen,Li, Weijian,Tang, Pei,Yang, Zhi
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p. 8143 - 8153
(2021/06/28)
-
- Method for synthesizing tetrahydroberberine and derivatives thereof
-
The invention provides a method for synthesizing tetrahydroberberine and derivatives thereof. Specifically, in the presence of an iridium metal catalyst precursor, a chiral diphosphine ligand, an acid and a halogen-containing additive, in a hydrogen atmosphere, a compound (II) is subjected to an asymmetric catalytic hydrogenation reaction in an organic solvent so as to prepare the compound (I).
- -
-
Paragraph 0106-0112
(2021/07/08)
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- Stereoselective construction of a berberine C-8 benzyl group for the synthesis of javaberine derivatives
-
Diastereoselective synthesis of 8-benzyltetrahydroprotoberberines was examined. Although Stevens rearrangement of N-benzylxylopinine resulted in poor yield and diastereoselectivity, benzylation of tetracyclic iminium successfully gave H8-H14 trans-benzyltetrahydroprotoberberines with high stereoselectivity.
- Kakigi, Rina,Nakano, Mai,Ueno, Ayana,Miyawaki, Akari,Tomioka, Kiyoshi,Yamamoto, Yasutomo
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p. 512 - 523
(2020/01/31)
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- Development of Pd(OAc)2-catalyzed tandem oxidation of C[sbnd]N, C[sbnd]C, and C(sp3)–H bonds: Concise synthesis of 1-aroylisoquinoline, oxoaporphine, and 8-oxyprotoberberine alkaloids
-
A catalytic tandem oxidation of C[sbnd]N, C[sbnd]C, and C(sp3)–H bonds is developed. This tandem oxidation is applied to two-step total syntheses of papaveraldine and pulcheotine A. Additionally, the total synthesis of liriodenine is achieved in six steps from homopiperonyl alcohol and 2-bromophenylacetonitrile by applying this catalytic tandem oxidation. Moreover, the direct conversion of xylopinine to 8-oxypseudopalmatine in a 76% yield demonstrates the versatility of this catalytic reaction.
- Nishimoto, Saeko,Nakahashi, Hiromichi,Toyota, Masahiro
-
supporting information
(2020/11/13)
-
- Green synthesis technology of rotundine sulfate
-
The invention provides a green synthesis technology of rotundine sulfate. The green synthesis technology comprises the following steps: firstly, taking pyrocatechol as a starting reactant, and carrying out esterification, acylation and nitration; then carrying out deoxygenation reduction to obtain 3,4-dimethoxyphenethylamine; then carrying out condensation on the obtained 3,4-dimethoxyphenethylamine and 2,3-dimethoxy benzaldehyde and reducing to obtain (3,4-dimethoxy)phenethyl(2,3-dimethoxy)benzylamine; finally, carrying out cyclization, reduction and sulfation on the obtained (3,4-dimethoxy)phenethyl(2,3-dimethoxy)benzylamine, so as to obtain finished-product rotundine sulfate. The invention develops a full-synthesis technology taking the pyrocatechol as a raw material, and provides an environment-friendly, low-cost and high-yield green synthesis technology for synthesizing the rotundine sulfate.
- -
-
-
- A General, Concise Strategy that Enables Collective Total Syntheses of over 50 Protoberberine and Five Aporhoeadane Alkaloids within Four to Eight Steps
-
A concise, catalytic, and general strategy that allowed efficient total syntheses of 22 natural 13-methylprotoberberines within four steps for each molecule is reported. This synthesis represents the most efficient and shortest route to date, featuring three catalytic processes: CuI-catalyzed redox-A3 reaction, Pd-catalyzed reductive carbocyclization, and PtO2-catalyzed hydrogenation. Importantly, this new strategy to the tetracyclic framework has also been applied to the collective concise syntheses of >30 natural protoberberines (without 13-methyl group) and five aporhoeadane alkaloids.
- Zhou, Shiqiang,Tong, Rongbiao
-
p. 7084 - 7089
(2016/05/19)
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- Synthesis of Tetrahydroisoquinoline Alkaloids and Related Compounds through the Alkylation of Anodically Prepared α-Amino Nitriles
-
α-Amino nitrile 2a was conveniently prepared in two individual steps from chiral hexafluorophosphate salt isoquinolinium (-)-8b including anodic cyanation as an efficient means to activate the sp3 C1-H bond of the THIQ nucleus. The lithiation o
- Benmekhbi, Lotfi,Louafi, Fadila,Roisnel, Thierry,Hurvois, Jean-Pierre
-
p. 6721 - 6739
(2016/08/16)
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- HEXAHYDRODIBENZO[A,G]QUINOLIZINE COMPOUND, PREPARATION METHOD THEREOF, PHARMACEUTICAL COMPOSITION AND USE THEREOF
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The present invention relates to a novel hexahydrodibenzo[a,g]quinoline compound represented by general formula (I) and its derivatives, enantiomer, diastereoisomer, raceme and mixtures thereof, as well as pharmaceutically acceptable salts thereof. The pr
- -
-
Paragraph 0092; 0093
(2014/04/03)
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- HEXAHYDRODIBENZO[A,G]QUINOLIZINE COMPOUND, PREPARATION METHOD THEREFOR, PHARMACEUTICAL COMPOSITION AND USE THEREOF
-
The present invention relates to a novel hexahydrodibenzo[a,g]quinoline compound represented by general formula (I) and its derivatives, enantiomer, diastereoisomer, raceme and mixtures thereof, as well as pharmaceutically acceptable salts thereof. The present invention further relates to a method for preparing the compound, and the compound has good prevention and treatment effect on neurological diseases, especially diseases associated with dopamine receptor and 5-hydroxytryptamine receptor. The bioactivity experiment demonstrates that, the compound is expected to be developed into a novel and potent chemical entity for treating diseases associated with dopamine receptor and 5-hydroxytryptamine receptor, especially schizophrenia, Parkinson's disease, drug addiction, migraine and so on.
- -
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Page/Page column
(2014/05/06)
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- Synthesis of alkaloids by stevens rearrangement of nitrile-stabilized ammonium ylides: (±)-laudanosine, (±)-laudanidine, (±)-armepavine, (±)-7-methoxycryptopleurine, and (±)-xylopinine
-
The Stevens rearrangement of nitrile-stabilized ammonium ylides in conjunction with the reductive removal of the nitrile function permits the facile construction of α-branched amines from α-aminonitriles. We employed this reaction sequence for the preparation of (±)-laudanosine, (±)-laudanidine and (±)-armepavine, (±)-7- methoxycryptopleurine, and (±)-xylopinine from two closely related and readily accessible bicyclic α-aminonitriles. The final products were obtained in high to almost quantitative yields (71-98%) from the quaternary ammonium salts obtained by N-alkylation of these starting materials.
- Orejarena Pacheco, Julio Cesar,Lahm, Günther,Opatz, Till
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p. 4985 - 4992
(2013/06/27)
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- Asymmetric synthesis of (S)-(-)-xylopinine. Use of the sulfinyl group as an ipso director in aromatic SE
-
Optically pure (S)-(-)-xylopinine 2 was prepared in three steps in 52% overall yield. Thus, condensation of the carbanion derived from (S)-4 with the (S)-(E)-sulfinylimine 5 gave a 2:1 mixture of tetrahydroisoquinolines 6a and 6b, differing only in configuration at sulfur. N-Desulfinylation of this mixture gave the diastereomeric sulfoxides which, without separation, were converted into (S)-(-)-xylopinine (2) with loss of the sulfinyl moieties under Pictet-Spengler conditions. This unprecedented ipso electrophilic substitution of a sulfinyl group may have synthetic implications beyond that described in this work.
- Mastranzo, Virginia M.,Yuste, Francisco,Ortiz, Benjamin,Sanchez-Obregon, Ruben,Toscano, Ruben A.,Garcia Ruano, Jose L.
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experimental part
p. 5036 - 5041
(2011/08/06)
-
- Compounds and Compositions for Modulating Lipid Levels and Methods of Preparing Same
-
The present technology relates to compounds of Formulas I-VI and methods of making and using such compounds. Methods of use include prevention and treatment of hyperlipidemia, hypercholesterolemia, hypertriglyceridemia, hepatic steatosis, and metabolic syndrome. Compounds disclosed herein also increase HDL-C, lower total cholesterol, LDL-cholesterol, and triglycerides and increase hepatic LDL receptor expression, inhibit PCSK9 expression, and activate AMP-activated protein kinase.
- -
-
Page/Page column 71; 74
(2011/02/15)
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- CORYDALINE DERIVATIVES USEFUL FOR REDUCING LIPID LEVELS
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The present technology relates to compounds of Formulas (V) and (VI) and methods of making and using such compounds. Methods of use include prevention and treatment of hyperlipidemia, hypercholesterolemia, hypertriglyceridemia, hepatic steatosis, and metabolic syndrome. Compounds disclosed herein also lower total cholesterol, LDL- cholesterol, and triglycerides and increase hepatic LDL receptor expression, inhibit PCSK9 expression, and activate AMP-activated potein kinase.
- -
-
Page/Page column 89
(2010/07/09)
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- COMPOUNDS, COMPOSITIONS AND METHODS FOR REDUCING LIPID LEVELS
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Compositions comprising extracts or isolated or purified compounds from plants of the genus Corydalis provide prevention and treatment of hyperlipidemia, hypercholesterolemia, hypertriglyceridemia, hepatic steatosis, and metabolic syndrome. Corydalis compounds and their derivatives of natural and synthetic origins lower total cholesterol, LDL-cholesterol, and triglycerides and increase hepatic LDL receptor expression and activate AMP-activated protein kinase. Specific stereoisomers of Corydalis compounds with lipid lowering activity include 14R-(+)-corypalmine, 14R,13S-(+)-corydaline, 14R-(+)-tetrahydropalmatin, (+)-corlumidin, d-(+)-bicuculline, and (+)-egenine.
- -
-
Page/Page column 38-39
(2009/03/07)
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- A variation of the Pictet-Spengler reaction via a sequential reduction-cyclization reaction of N-acylcarbamates: synthesis of 1-substituted tetrahydroisoquinoline derivatives
-
A new variation of the Pictet-Spengler reaction for the synthesis of 1-substituted tetrahydroisoquinoline derivatives has been developed. The reaction employs the reduction of N-acylcarbamates by DIBAL-H followed by simultaneous cyclization mediated by BF3·OEt2. The synthetic potential of this method has been illustrated by the synthesis of the tetrahydroisoquinoline alkaloids, (±)-xylopinine, (±)-laudanosine, (±)-8-oxo-O-methylbharatamine, and (±)-isoindoloisoquinolone.
- Kuhakarn, Chutima,Panyachariwat, Nattakan,Ruchirawat, Somsak
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p. 8182 - 8184
(2008/03/14)
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- Synthesis of both enantiomers of protoberberines via laterally lithiated (S)-4-isopropyl-2-(o-tolyl)-oxazolines
-
The addition of the laterally lithiated (S)-4-isopropyl-2-(o- tolyl)oxazoline (1) to 6,7-dimethoxy-3,4-dihydroisoquinoline (2) proceeded in modest diastereoselectivity. However, the addition products (3a) and (3b) were easily separated by column chromatography over silica gel. Acid-catalyzed lactamization of 3a and 3b followed by LiAlH4-reduction afforded the corresponding optically pure protoberberines (8a) and (8b), respectively. This procedure was successfully applied to the synthesis of both enantiomers of xylopinine and bharatamine.
- Fukuda, Tsutomu,Iwao, Masatomo
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p. 701 - 720
(2008/09/18)
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- Enantioselective synthesis of (+)-(S)-laudanosine and (-)-(S)-xylopinine
-
The study presents a new pathway for the enantioselective synthesis of benzylisoquinoline alkaloids. The key steps of the synthesis of (+)-(S)-laudanosine (1) and (-)-(S)-xylopinine (2) are a Sonogashira coupling that builds up the C1-C8a bond of the benzylisoquinoline skeleton, an intramolecular Ti-catalyzed hydroamination of an alkyne, and a subsequent enantioselective imine reduction according to Noyori's protocol.
- Mujahidin, Didin,Doye, Sven
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p. 2689 - 2693
(2007/10/03)
-
- LC-NMR and LC-MS analysis of 2,3,10,11-oxygenated protoberberine metabolites in Corydalis cell cultures
-
The metabolism of 2,3,10,11-oxygenated protoberberine alkaloids was studied in cell cultures of Corydalis species. Without prior isolation, the structures of the metabolites were determined by LC-MS and LC-NMR analyses. Tetrahydropseudocoptisine α-N-metho salt, pseudoprotopine, and pseudomuramine were identified for the first time, and preliminary evidence for metabolic pathways to the formation of these alkaloids were obtained.
- Isawa, Kinuko,Kuribayashi, Ayako,Sugiura, Makiko,Moriyasu, Masataka,Lee, Dong-Ung,Wiegrebe, Wolfgang
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p. 1229 - 1238
(2007/10/03)
-
- Asymmetric synthesis of the protoberberine alkaloid (s)-(-)-xylopinine using enantiopure sulfinimines
-
A concise enantioselective synthesis of (S)-(-)-xylopinine (1) is described involving the addition of the laterally lithiated derivative of o-tolunitrile of 16 to enantiopure sulfinimine (+)-14. Treatment of the resulting cyano sulfinamide adduct (-)-17b with DIBAL-H accomplishes five operations in a single pot and furnishes the cyclic imine (+)-18 in good yield. Reduction and cyclization affords (S)-(-)-1. Alternatively basic hydrolysis of 17b,c gives isoquinolone 21 that is cyclized and reduced to give (S)-(-)-1.
- Davis, Franklin A.,Mohanty, Pradyumna K.
-
p. 1290 - 1296
(2007/10/03)
-
- The Polonovski-Potier reaction of berbine N-oxides. Synthesis of 8-hydroxymethyl and 8-methylberbines
-
The Polonovski-Potier reaction of trans and cis berbines N-oxides was studied. The 8-cyano derivative obtained from trans N-oxides were used to synthesize 8-hydroxymethyl and 8-methyl berbines. This procedure was applied to the stereocontroled synthesis of (8R, 14S)-(-)-8-methylcanadine from (14S)-(-)-canadine. (C) 2000 Elsevier Science Ltd.
- Suau, Rafael,Nájera, Francisco,Rico, Rodrigo
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p. 9713 - 9723
(2007/10/03)
-
- Aryl radical cyclizations: One-pot syntheses of protoberberine and pavine alkaloids
-
(equation presented) Treatment of 2-(2′-bromo-β-phenethyl)isocarbostyrils 7 with AIBN Bu3SnH in boiling benzene gave 8-oxoberbines 3 in good yields. A similar treatment of 2-(2′-bromo-β-phenethyl)isoquinolinium bromides 6 and their nor- and hom
- Orito, Kazuhiko,Satoh, Yoshitaka,Nishizawa, Hidetoshi,Harada, Rika,Tokuda, Masao
-
p. 2535 - 2537
(2007/10/03)
-
- 2-(o-tolyl)-4,4-dimethyl-2-oxazolines - A new vehicle for facile convergent synthesis of protoberberine alkaloids
-
A single step synthesis of 8-oxotetrahydroprotoberberines (57-82%) by the addition of lithiated 2-(o-tolyl)-4,4-dimethyl-2-oxazolines on 3,4- dihydroisoquinolines is described.
- Singh, Kamal Nain
-
p. 4391 - 4392
(2007/10/03)
-
- Chiral auxiliary mediated pictet-spengler reactions: Asymmetric syntheses of (-)-laudanosine, (+)-glaucine and (-)-xylopinine
-
Cyclohexyl-based chiral auxiliaries can be used effectively in an asymmetric Pictet-Spengler synthesis of tetrahydroisoquinoline, aporphine and protoberbine alkaloids. Using this strategy, concise asymmetric syntheses of (-)-laudanosine, (+)-glaucine and (+)- xylopinine have been accomplished.
- Comins, Daniel L.,Thakker, Paresh M.,Baevsky, Matthew F.,Badawi, Mohamed M.
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p. 16327 - 16340
(2007/10/03)
-
- Synthesis of isoquinolines from 2-phenylethylamines, amides, nitriles and carboxylic acids in polyphosphoric acid
-
A convenient one pot synthesis of 1-, 1.3-substituted 3,4-dihydroisoquinolines 5 enamines 10 and 3-oxo-2,3-dihydroisoquinolines 18 as well as of enamides 22 of isoquinoline from 2-phenyl-, 1,2-diphenylethylamines, phenylacetamides, phenylacetonitriles, N-acylphenylethylamines and carboxylic acids in nonaqueous media has been accomplished.
- Venkov, Atanas P.,Ivanov, Ilian I.
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p. 12299 - 12308
(2007/10/03)
-
- A novel asymmetric route to the 1,3-disubstituted tetrahydroisoquinoline, (-)-argemonine
-
Chiral bicyclic lactam 13 was converted to the natural product (-)-argemonine 9 in six steps. This novel route to argemonine represents a general strategy for the preparation of chiral 1,3-disubstituted tetrahydroisoquinolines.
- Munchhof, Michael J.,Meyers
-
p. 4607 - 4610
(2007/10/03)
-
- A FACILE ROUTE TO TETRAHYDROISOQUINOLINE ALKALOIDS VIA SULFOXIDE MEDIATED CYCLIZATION
-
A facile route to 1,2,3,4-tetrahydroisoquinoline framework has been developed by employing the sulfoxide mediated cyclization reaction.Utilizing the reaction developed some naturally occurring isoquinoline alkaloids have been synthesized.
- Takano, Seiichi,Iida, Hirokazu,Inomata, Kohei,Ogasawara, Kunio
-
-
- Isoquinoline frameworks via aryl radical-initiated 1,6-cyclization
-
Exclusive 1,6-cyclization occurred to afford isoquinoline frameworks when the enamide and the enamine substrates bearing exo-olefin moiety were treated with tri-n-butyltin hydride in the presence of radical initiator (9a, b → 12a, b; 13a, b → 18a, b), respectively. On the other hand, competitive 1,6- and 1,5-cyclization occurred to give a mixture of isoquinolone and isoindolone frameworks when the enamide substrates bearing endo-olefin moiety were treated under the same conditions (22a, b → 26a, b and 27a, b).
- Takano,Suzuki,Kijima,Ogasawara
-
p. 2315 - 2318
(2007/10/02)
-
- Novel Photochemical-Diradical Cyclization Methods for Protoberberine Alkaloid Synthesis. Preparation of (+/-)-Xylopinine and (+/-)-Stylopine
-
A new synthetic approach to members of the protoberberine alkaloid family based upon a photochemical-diradical cyclization methodology is described.
- Dai-Ho, Ginny,Mariano, Patrick S.
-
p. 704 - 706
(2007/10/02)
-
- THE PROTOBERBERINE ALKALAOIDS OF STEPHANIA SUBEROSA
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Six new protoberberines were found in Stephania suberosa root extracts: (-)-tetrahydrostephabine, (-)-stephabinamine, stephabine, 8-oxopseudopalmatine, (-)-trans-xylopinine N-oxide and (-)-cis-xylopinine N-oxide.Ten known alkaloids were also detected: (-)-tetrahydropalmatine, (-)tetrahydropalmatrubine, (-)-stepholidine, (-)-kikemanine, (-)-capaurimine, (-)-coreximine, (-)-corytenchine, (-)-discretine, pseudopalmatine and (-)-xylopinine. Key Word Index--Stephania suberosa; Menispermaceae; roots ; protoberberines; alkaloids.
- Patra, Amarendra,Montgomery, Craig T.,Freyer, Alan J.,Guinaudeau, Helene,Shamma, Maurice,et al.
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p. 547 - 550
(2007/10/02)
-
- Chemical Transformation of Protoberbines. XI. A Novel Synthesis of 2,3,10,11-Tetraoxygenated Protoberberine Alkaloids from Corresponding 2,3,9,10-Tetraoxygenated Protoberberine Alkaloids.
-
2,3,9,10-Tetraoxygenated protoberberin alkaloids, berberine (1a), palmatine (1b), and coptisine (1c) were efficiently converted into the corresponding 12-hydroxy-2,3,10,11-tetraoxygenated protoberberines (6a, 6b, 6c) through an oxidative C8-C8a bond cleav
- Hanaoka, Miyoji,Cho, Won Jea,Marutani, Mari,Mukai, Chisato
-
p. 195 - 199
(2007/10/02)
-
- TRANSFORMATION OF 2,3,9,10-TETRAOXYGENATED PROTOBERBERINE ALKALOIDS INTO 2,3,10,11-TETRAOXYGENATED PROTOBERBERINE ALKALOIDS
-
2,3,10,11-Tetraoxygenated tetrahydroprotoberberine (6) were synthesized from the corresponding 2,3,9,10-tetraoxygenated protoberberine alkaloids (1) through oxidative C8-C8a bond cleavage, photocyclization, and deoxygenation.
- Hanaoka, Miyoji,Marutani, Mari,Saitoh, Kazuhiro,Mukai, Chisato
-
p. 2927 - 2930
(2007/10/02)
-
- NON-OXIDATIVE PHOTOCYCLIZATION OF 2-AROYL-1-METHYLENE-1,2,3,4-TETRAHYDROISOQUINOLINES
-
Non-oxidative photocyclization of the enamides (2c,d,e) in benzene at low temperature afforded a new type of the lactams (4c,d,e) and (8) which have a common dihydrobenzene moiety and were readily transformed into the corresponding dehydrolactams (5c,d,e) and (7), thus firmly established the reaction course of photocyclization of these enamides under non-oxidative condition.
- Naito, Takeaki,Katsumi, Kotomi,Tada, Yukiko,Ninomiya, Ichiya
-
p. 775 - 778
(2007/10/02)
-
- Synthetic Studies on Protoberberine Alkaloids
-
Condensation of homoveratrylamine with substituted isochroman-3-ones (3a-c) affords N-β-(3,4-dimethoxyphenethyl)arylacetamides (4a-c).Treatment of 4a-c with POCl3 and subsequent NaBH4 reduction of the reaction products furnish (+/-)-2,3,9,10,11-pentamethoxytetrahydroprotoberberine (2a), (+/-)-12-hydroxymethyl-2,3,9,10,11-pentamethoxytetrahydroprotoberberine (2b) and (+/-) nor coralydine (2c), respectively.Oxidation of 2a with iodine furnishes 2,3,9,10,11-pentamethoxyprotoberberinium salt (1).Carbon-13 NMR assignments of 2c, 3b, 3c, 4b and 4c are also reported.
- Patra, Amarendra,Mukhopadhyay, Prabir K.,Ghosh, Gargi
-
p. 173 - 175
(2007/10/02)
-
- PALLADIUM CATALYZED INSERTION OF CARBON MONOXIDE INTO BENZYL-TETRAHYDROISOQUINOLINES. A NEW SYNTHESIS OF BERBINE ALKALOIDS
-
A new total synthesis of the berbine alkaloid ring system has been achieved.Palladium catalyzed insertion of carbon monoxide into the 1-(2-bromobenzyl)-substituted-1,2,3,4-tetrahydroisoquinolines (1a-d) by the use of catalytic amounts of palladium diaceta
- Pandey, Ganesh D.,Tiwari, Kamala P.
-
p. 1213 - 1214
(2007/10/02)
-
- Total Synthesis of the Protoberberine Alkaloid (-)-Xylopinine by Photochemical 1,3-Asymmetric Induction
-
The protoberberine alkaloid, xylopinine (12), has been synthesised in an optically active form, a key reaction being the photochemical cyclisation of optically active 1,2,3,4-tetrahydro-6,7-dimethoxy-3-methoxycarbonyl-1-methylene-2-veratroylisoquinoline (4) with 1,3-asymmetric induction.
- Kametani, Tetsuji,Takagi, Nanami,Toyota, Masahiro,Honda, Toshio,Fukumoto, Keiichiro
-
p. 2830 - 2834
(2007/10/02)
-
- TOTAL SYNTHESIS OF OPTICALLY ACTIVE PROTEBERBERINE ALKALOID, XYLOPININE, BY 1,3-ASYMMETRIC INDUCTION IN PHOTOLYSIS
-
Total synthesis of optically active xylopinine (11) was achieved by irradiation of the enamide (4) as a key reaction.
- Kametani, Tetsuji,Takagi, Nanami,Toyota, Masahiro,Honda, Toshio,Fukumoto, Keiichiro
-
p. 591 - 594
(2007/10/02)
-
- Synthesis of Heterocycles via Lactones: Part VI Condensation of Bromo Esters with β-Phenethylamines, a New Route to Berbines: Synthesis of (+/-)-Xylopinine, (+/-)-Scoulerine, Isocoptisine and Pseudoepitetrahydroberberine
-
A new route involving the generation of a tricyclic lactam intermediate in one-step has been developed for the synthesis of 2,3,10,11-tetraoxygenated berbine alkaloids.Three such alkaloids have been synthesized besides scoulerine which is 2,9-dihydroxy-3,10-dimethoxyberbine (11).
- Pandey, G. D.,Tiwari, K. P.
-
p. 272 - 275
(2007/10/02)
-
- A regiospecific synthesis of protoberberine alkaloids
-
The protoberberine skeleton has been prepared in two steps from N-benzyl-3,4-dihydroisoquinolinium salts.Treatment of the salts with the anion of methyl methylthiomethylsulfoxide yields mixtures of diastereomeric adducts that cyclize on heating with concentrated hydrochloric acid to dihydroprotoberberines.The latter compounds may be reduced to their tetrahydro analogues with sodium borohydride, oxidized to protoberberinium salts with iodine, or converted to 13-methyltetrahydroprotoberberines by treatment with formaldehyde according to an established procedure.The method has been applied successfully to the synthesis of (+/-)-tetrahydropalmatine, palmatine iodide, (+/-)-xylopinine, (+/-)-sinactine, and (+/-)-corydaline.N-Benzylisoquinolinium salts may be used in place of their dihydro analogues as starting materials in this synthesis, thereby extending the range of substitution patterns potentially available.
- Kiparissides, Zinovia,Fichtner, Robert H.,Poplawski, Janusz,Nalliah, Bala C.,MacLean, David B.
-
p. 2770 - 2779
(2007/10/02)
-