84-38-8

Upstream product

• 113038-86-1 2,3,9,10-tetramethoxy-isoquino[3,2-a]isoquinolinylium; bromide 
• 186581-53-3 diazomethane 
• 47346-21-4 2,3-dihydroxy-9,10-dimethoxyprotoberberine 
• 4697-61-4 (+/-)-12-bromotetrahydropalmatine 
• 81701-50-0 (±)-8-oxotetrahydropalmatine 
• 26067-60-7 2,3,9,10-tetramethoxy-5,8-dihydro-6H-isoquinolino[3,2-α]isoquinoline 
• 2288-47-3 dl-tetrahydropalmatine methiodide 
• 113557-41-8 7,8-dimethoxy-2-(3,4-dimethoxyphenethyl)-1,2,3,4-tetrahydroisoquinolin-3-one 
• 79809-15-7 N-<2-(3,4-dimethoxyphenyl)ethyl>(3,4-dimethoxy-2-hydroxymethyl)-phenylacetamide 
• 86639-32-9 (+/-)-1-bromotetrahydropalmatine 
• 107887-62-7 5,6,13,13a-tetrahydro-2,3,9,10-tetramethoxy-5-oxo-8H-dibenzo<3>quinolizine ethylene acetal 
• 108585-32-6 3',4'-dihydro-6,6',7,7'-tetramethoxy-spiro<2H-indene-2,1'(2'H)-isoquinolin>-1(3H)-one 
• 98192-23-5 dihydropalmatinium hydroxide 
• 50-00-0 formaldehyd 

Downstream Products

• 3520-14-7 (R)-(+)-tetrahydropalmatine 
• 77519-57-4 (S)-(-)-8-oxoxylopinine 

Relevant academic research and scientific papers

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.

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).

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.

Bis(mandelato)borate: An effective, inexpensive spiroborate anion for chiral resolution

Bis(mandelato)borate [B(Man)2]- (R- or S-) anions are simply prepared and appear widely effective for resolution of racemic cations. Three examples demonstrate their scope; the alkaloid tetrahydropalmatine (THP), 1,2-diaminopropane (1,2-dap) and the metal-organic complex [Co(phen)3]3+ are readily resolved, either by a facile one-pot procedure, or via counter-ion metathesis.

Asymmetric total synthesis and identification of tetrahydroprotoberberine derivatives as new antipsychotic agents possessing a dopamine D1, D2 and serotonin 5-HT1A multi-action profile

An effective and rapid method for the microwave-assisted preparation of the key intermediate for the total synthesis of tetrahydroprotoberberines (THPBs) including l-stepholidine (l-SPD) was developed. Thirty-one THPB derivatives with diverse substituents on A and D ring were synthesized, and their binding affinity to dopamine D1, D2 and serotonin 5-HT 1A and 5-HT2A receptors were determined. Compounds 18k and 18m were identified as partial agonists at the D1 receptor with Ki values of 50 and 6.3 nM, while both compounds act as D2 receptor antagonists (Ki = 305 and 145 nM, respectively) and 5-HT1A receptor full agonists (Ki = 149 and 908 nM, respectively). These two THPBs compounds exerted antipsychotic actions in animal models. Further electrophysiological studies employing single-unit recording in intact animals demonstrated that 18k-excited dopaminergic (DA) neurons are associated with its 5-HT1A receptor agonistic activity. These results suggest that these two compounds targeted to multiple neurotransmitter receptors may present novel lead drugs with new pharmacological profiles for the treatment of schizophrenia.

Asymmetric synthesis of (S)-(-)-tetrahydropalmatine and (S)-(-)-canadine via a sulfinyl-directed Pictet-Spengler cyclization

(S)-(-)-Tetrahydropalmatine 2 and (S)-(-)-canadine 4 were synthesized in three steps from (S)-6, in 33% and 34% overall yield, respectively. Thus, condensation of the (S)-(E)-sulfinylimines 10 and 11 with the carbanion derived from (S)-6 gave the tetrahydroisoquinolines 12 and 13, respectively, which upon TFA induced N-desulfinylation, and subsequent microwave assisted Pictet-Spengler cyclization effected both cyclization and C-desulfinylation producing (S)-(-)-tetrahydropalmatine 2 and (S)-(-)-canadine 4 in optically pure form.

Preparation and evaluation of a molecularly imprinted polymer derivatized silica monolithic column for capillary electrochromatography and capillary liquid chromatography

A method for preparation of molecularly imprinted polymer (MIP) derivatized onto the surface of a monolithic silica capillary column was successfully developed. The vinyl groups were first introduced onto the silica monolith by immobilization of γ-methacryloxypropyltrimethoxysilane. Then the MIP coating was copolymerized and anchored onto the surface of the silica monolith. Acetonitrile was selected as porogen (solvent). The other preparation conditions, such as monomer concentration, temperature, and time of polymerization, were systematically studied. The obtained MIP-derivatized silica monolith using L-tetrahydropalmatine (L-THP) and (5S,11S)-(-)-Troeger's base (S-TB) as the imprinted template, respectively, was characterized in terms of the retention behavior of thiourea and toluene. Under the optimized CEC conditions, baseline enantioseparations of THP and TB were achieved in 4 min though the effective length of the columns was 8.5 cm. The result indicates that enough recognition sites were on the surface of silica monolith, resulting in strong recognition ability. Compared with a MIP organic monolith, the MIP-derivatized silica monolith exhibits better column efficiency and stability in CEC. Additionally, the comparison of these two kinds of monolithic columns was performed by capillary liquid chromatography. The separation on MIP-derivatized silica monolith was superior to that on the organic monolith.

Asymmetric synthesis of tetrahydropalmatine via tandem 1,2-addition/ cyclization

The enantioselective synthesis of both enantiomers of tetrahydropalmatine (2) (ee = 98%), a natural alkaloid belonging to the tetrahydroprotoberberine family, is described. The key step of this total synthesis is based on our tandem 1,2-addition/ring-closure methodology employing lithiated methylbenzamide and benzaldehyde SAMP or RAMP hydrazones as substrates. An initial route was investigated for the formation of N- and 3-substituted dihydroisoquinolones starting from 2-substituted benzaldehyde SAMP hydrazones, but although high diastereoselectivity was achieved, only disappointing yields were obtained. In our subsequent synthetic strategy, 2,3-dimethoxy-6-methylbenzamide 6 and 3,4-dimethoxybenzaldehyde SAMP or RAMP hydrazone 19 gave the dihydroisoquinolones 20 in high diastereomeric purity (de ≥ 96%) and reasonable yield (54-55%), taking into account the complex functionalities established in one step. Cleavage of the N-N bond of the chiral auxiliary and reduction of the carbonyl group of the amide moiety were performed in the same step, and the resulting tetrahydroisoquinolines 22 (ee = 99%) were N-functionalized by treatment with various electrophiles to investigate the ring closure by Pummerer, Friedel-Crafts, and Pomeranz-Fritsch reactions. The Pummerer cyclization led to the formation of (S)-(-)-2 with slight racemization (ee = 89%), whereas the Friedel-Crafts reaction proved to be unsuccessful. Finally, Pomeranz-Fritsch-type cyclization afforded the desired title compound (R)-(+)-2 in excellent enantioselectivity in 9% overall yield over seven steps and after optimization of the last step (S)-(-)-2 in 17% overall yield.

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

Convenient synthesis of 2,3,9,10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids

New and convenient synthesis of 2,3,9,10-tetraoxygenated protoberberine alkaloids and their 13-methyl alkaloids through the same intermediates was developed. Acylation of the brominated benzylphenethylamine (13) with α- chloro-α-(methylthio)acetyl chloride, followed by cyclization with stannic chloride, furnished the key intermediates 4-methylthio-3- phenethylisoquinolin-3-ones (14), which were methylated to provide their methyl derivatives (17). Both isoquinolin-3-ones (14, 17) were easily transformed into protoberberine alkaloids (16) and their 13-methyl alkaloids (21) in good yield.