919082-30-7

Upstream product

• 122775-35-3 3,4-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 
• 53969-89-4 (Z/E)-ethyl 3,4-dimethoxy-α-nitrocinnamate 
• 6957-27-3 3,4-dihydropapaverine 
• 93-40-3 (3,4-Dimethoxyphenyl)acetic acid 
• 139-76-4 N-(3,4-dimethoxyphenethyl)-2-(3,4-dimethoxyphenyl)acetamide 
• 7417-21-2 2-(3,4-dimethoxyphenyl)ethyl alcohol 
• 681431-26-5 4-(3,4-dimethoxy-phenyl)-5-{4,5-dimethoxy-2-[2-(toluene-4-sulfonyloxy)-ethyl]-phenyl}-1H-pyrrole-2-carboxylic acid ethyl ester 
• 681431-23-2 4-(3,4-dimethoxyphenyl)-5-[2-(2-hydroxyethyl)-4,5-dimethoxyphenyl]-1H-pyrrole-2-carboxylic acid ethyl ester 
• 681431-24-3 1-(3,4-dimethoxyphenyl)-8,9-dimethoxy-5,6-dihydropyrrolo[2,1-a]isoquinoline-3-carboxylic acid ethyl ester 
• 681431-22-1 5-bromo-4-(3,4-dimethoxyphenyl)-1H-pyrrole-2-carboxylic acid ethyl ester 
• 681431-18-5 2-(2-hydroxyethyl)-4,5-dimethoxyphenylboronic acid 
• 516465-80-8 4-bromo-1H-pyrrole-1,2-dicarboxylic acid 1-tert-butyl 2-ethyl ester 
• 433267-55-1 4-bromo-1H-pyrrole-2-carboxylic acid ethyl ester 

Downstream Products

• 1026618-82-5 C₃₁H₃₁NO₈ 

Relevant academic research and scientific papers

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.

A Modular Synthesis of the Lamellarins: Total Synthesis of Lamellarin G Trimethyl Ether

A modular synthesis of the lamellarin family of natural products has been developed that is based on the application of three iterative halogenation/cross-coupling reaction sequences. The ability to halogenate the pyrrole core in a regioselective fashion, even in the presence of highly electron-rich aryl substituents, has been established. The compatibility of Suzuki coupling conditions with free alcohols and phenols in the boronic acids has been employed to reduce the number of protection/deprotection steps. Indeed, the presence of a free phenol on boronic acid 3 has been determined to be critical for the successful final coupling in route to lamellarin G trimethyl ether, since protected versions fail to undergo coupling.