181423-71-2

Upstream product

• 519753-21-0 2-[1-(3,4-dimethoxyphenyl)-8,9-dimethoxy-5,6-dihydropyrrolo[2,1-a]isoquinolin-2-yl]-4,5-dimethoxyphenyl ethyl carbonate 
• 120-14-9 3,4-dimethoxy-benzaldehyde 
• 2859-78-1 4-Bromoveratrole 
• 122775-35-3 3,4-Dimethoxyphenylboronic acid 
• 20628-06-2 2-hydroxy-4,5-dimethoxyacetophenone 
• 2033-89-8 3,4-dimethoxyphenol 
• 74-88-4 methyl iodide 
• 169133-03-3 3-nitro-6,7-dimethoxycoumarin 
• 5884-22-0 1-(3,4-dimethoxybenzyl)-6,7-dimethoxy-3.4-dihydroisoquinoline hydrochloride 
• 139-76-4 N-(3,4-dimethoxyphenethyl)-2-(3,4-dimethoxyphenyl)acetamide 
• 93-40-3 (3,4-Dimethoxyphenyl)acetic acid 
• 1034028-87-9 (Z)-ethyl 2-benzyloxy-4,5-dimethoxy-α-nitrocinnamate 
• 681431-19-6 2-hydroxy-4,5-dimethoxyphenylboronic acid 
• 681431-25-4 2-bromo-1-(3,4-dimethoxyphenyl)-8,9-dimethoxy-5,6-dihydropyrrolo[2,1-a]isoquinoline-3-carboxylic acid ethyl ester 

Relevant academic research and scientific papers

Scalable Total Syntheses of Some Natural and Unnatural Lamellarins: Application of a One-Pot Domino Process for Regioselective Access to the Central 1,2,4-Trisubstituted Pyrrole Core

Short and scalable total syntheses of lamellarin G trimethyl ether, lamellarin D trimethyl ether, lamellarin H, lamellarin ?, dihydrolamellarin ?, and lamellarin U have been realized in four to six linear steps with an overall yield of ≤22%. Highlights of

Synthesis of Lamellarin G Trimethyl Ether by von Miller–Pl?chl-Type Cyclocondensation

A concise synthesis of lamellarin G trimethyl ether based on a von Miller–Pl?chl-type cyclocondensation of a deprotonated α-amino nitrile with an α,β-unsaturated ketone as the key step was developed. The general strategy does not rely on molecular symmetry and allows for the independent variation of the substitution pattern.

Application of differential reactivity towards synthesis of lamellarin and 8-oxoprotoberberine derivatives: Study of photochemical properties of aryl-substituted benzofuran-8-oxoprotoberberines

A unique differential reactivity between dihydroisoquinolines and 3-nitrocoumarins was observed and was exploited for the efficient construction of lamellarins and their isomeric benzofuran-8-oxoprotoberberine derivatives under acid-catalyzed or base-promoted conditions. Further, these prepared aryl-substituted benzofuran-8-oxoprotoberberine derivatives bearing electron-donating substituents on benzofuran moiety are found to be benchtop stable but light-sensitive, and can undergo oxidative ring-opening reaction to give the corresponding keto products when exposed to visible light under aerobic conditions.

Acid-Mediated Intermolecular [3 + 2] Cycloaddition toward Pyrrolo[2,1-a]isoquinolines: Total Synthesis of the Lamellarin Core and Lamellarin G Trimethyl Ether

A novel one-pot reaction has been developed for the efficient synthesis of pyrrolo[2,1-a]isoquinolines and 1-dearyllamellarin core from (E)-(2-nitrovinyl)benzenes and azomethine ylides generated in situ. This strategy provides a concise total synthesis of

A high-yielding modular access to the lamellarins: Synthesis of lamellarin G trimethyl ether, lamellarin η and dihydrolamellarin η

A deprotonated α-aminonitrile serves as a key intermediate in a highly efficient (95 % per step on average; see scheme) modular synthetic approach to the lamellarin alkaloids. Its reaction with an α,β- unsaturated aldehyde forms the central pyrrole ring in a one-pot procedure. The construction of the fused pentacyclic skeleton is completed by a microwave-assisted Ullmann-type lactone formation.

Lamellarins as inhibitors of P-glycoprotein-mediated multidrug resistance in a human colon cancer cell line

Chemical analysis of a Didemnum sp. (CMB-01656) collected during scientific Scuba operations off Wasp Island, New South Wales, yielded five new lamellarins A1 (1), A2 (2), A3 (3), A4 (4) and A5 (5) and eight known lamellarins C (6), E (7), K (8), M (9), S (10), T (11), X (12) and χ (13). Analysis of a second Didemnum sp. (CMB-02127) collected during scientific trawling operations along the Northern Rottnest Shelf, Western Australia, yielded the new lamellarin A6 (14) and two known lamellarins G (15) and Z (16). Structures were assigned to 1-16 on the basis of detailed spectroscopic analysis with comparison to literature data and authentic samples. Access to this unique library of natural lamellarins (1-16) provided a rare opportunity for structure-activity relationship (SAR) investigations, probing interactions between lamellarins and the ABC transporter efflux pump P-glycoprotein (P-gp) with a view to reversing multidrug resistance in a human colon cancer cell line (SW620 Ad300). These SAR studies, which were expanded to include the permethylated lamellarin derivative (17) and a series of lamellarin-inspired synthetic coumarins (19-24) and isoquinolines (25-26), successfully revealed 17 as a promising new non-cytotoxic P-gp inhibitor pharmacophore. Copyright

Modular total syntheses of lamellarin G trimethyl ether and lamellarin S

Modular total syntheses of the title compounds 2 and 3 are reported. The key pyrrolic building block 8 was prepared from the readily accessible pyrrole 6 via a di-iodination/mono-deiodination sequence. Suzuki-Miyaura cross-coupling of compound 8 with boronate ester 9 afforded lactone 10. Bromination of compound 10 followed by N-alkylation under Mitsunobu conditions afforded the fully substituted pyrrole 13 that engaged in a second Suzuki-Miyaura cross-coupling reaction with boronic acid 14 to give compound 15. Hydrolysis of the ester moiety within the last compound afforded acid 16 that engaged in a decarboxylative Heck cyclization process to give lamellarin G trimethyl ether (3). A related sequence of reactions starting from building block 8 and using the isopropoxy-substituted arenes 22, 25 and 27 has allowed for the completion of the first total synthesis of lamellarin S (2). The first total synthesis of the marine alkaloid lamellarin S is described.

Modular total synthesis of lamellarin G trimethyl ether

A modular synthesis of the lamellarin G trimethyl ether has been developed based on the application of several reaction sequences which include Friedel-Crafts acylation, esterification, haloarylation, and oxidative cyclization. The formation of pyrrolo [2

Synthesis of lamellarin U and lamellarin G trimethyl ether by alkylation of a deprotonated α-aminonitrile

(Chemical Equation Presented) 1,2,3,4-Tetrahydroisoquinoline-1- carbonitriles can serve as starting materials for the one-pot synthesis of 5,6-dihydropyrrolo[2,1a]isoquinolines and 1-benzyl-3,4-dihydroisoquinolines. The latter compounds were transformed to lamellarin G trimethyl ether and lamellarin U in short reaction sequences. This method allows the introduction of acid-sensitive protecting groups for the phenolic hydroxy functions which would be cleaved under the harsh conditions of the classical Bischler-Napieralski reaction.

Total synthesis of natural and unnatural lamellarins with saturated and unsaturated D-rings

(Chemical Equation Presented) Twenty-eight natural and unnatural lamellarins with either a saturated or an unsaturated D-ring were synthesized according to our developed synthetic route. The key step involved the Michael addition/ring closure (Mi-RC) of the benzyldihydroisoquinoline and α-nitrocinnamate derivatives, which provided the 2-carboethoxypyrrole intermediates in moderate to good yields (up to 78% yield). Subsequent hydrogenolysis/lactonization furnished lamellarins with a saturated D-ring in excellent yields (up to 93% yield). DDQ oxidation of the saturated lamellarin acetates led directly to the corresponding unsaturated analogues in 54-95% yield. In addition, only two steps in our developed strategy require column chromatography.