98977-48-1

Upstream product

• 830-09-1 3-(4'-methoxyphenyl)propenoic acid 
• 943-89-5 (E)-3-(4-methoxyphenyl)acrylic acid 
• 123-11-5 4-methoxy-benzaldehyde 
• 459-32-5 (E)-4-fluorocinnamic acid 
• 34446-64-5 (E)-3-(4-methoxyphenyl)propenoyl chloride 

Downstream Products

• 116108-67-9 3,4-bis(4-methoxyphenyl)cyclobutane-1,2-dicarboxylic acid 
• 36650-62-1 dimethyl (1R*,2S*,3R*,4S*)-3,4-bis(4-methoxyphenyl)cyclobutane-1,2-dicarboxylate 
• 1449388-91-3 C₂₆H₂₄O₅ 
• 1449389-18-7 C₂₅H₁₉NO₃S 
• 1449389-22-3 C₂₅H₁₉NO₃S 
• 76361-69-8 7-methoxy-2-[(1E)-2-(4-methoxyphenyl)ethenyl]-4H-1-benzopyran-4-one 
• 126525-79-9 2-[(1E)-2-(4-methoxyphenyl)ethenyl]-6-methyl-4H-1-benzopyran-4-one 
• 51138-53-5 (E)-2-(4-methoxystyryl)-4H-chromen-4-one 
• 126525-75-5 1-(2-hydroxyphenyl)-3-[2-(4-methoxyphenyl)ethenyl]propane-1,3-dione 
• 126525-76-6 2-hydroxy-5-methyl-ω-(p-methoxy)cinnamoylacetophenone 

Relevant academic research and scientific papers

Photocatalytic Oxidative [2+2] Cycloelimination Reactions with Flavinium Salts: Mechanistic Study and Influence of the Catalyst Structure

Flavinium salts are frequently used in organocatalysis but their application in photoredox catalysis has not been systematically investigated to date. We synthesized a series of 5-ethyl-1,3-dimethylalloxazinium salts with different substituents in the positions 7 and 8 and investigated their application in light-dependent oxidative cycloelimination of cyclobutanes. Detailed mechanistic investigations with a coumarin dimer as a model substrate reveal that the reaction preferentially occurs via the triplet-born radical pair after electron transfer from the substrate to the triplet state of an alloxazinium salt. The very photostable 7,8-dimethoxy derivative is a superior catalyst with a sufficiently high oxidation power (E=2.26 V) allowing the conversion of various cyclobutanes (with Eox up to 2.05 V) in high yields. Even compounds such as all-trans dimethyl 3,4-bis(4-methoxyphenyl)cyclobutane-1,2-dicarboxylate can be converted, whose opening requires a high activation energy due to a missing pre-activation caused by bulky adjacent substituents in cis-position.

Substituted cinnamic anhydrides act as selective inhibitors of acetylcholinesterase

Cinnamic anhydrides have been shown to be more than reactive reagents, but they also act as inhibitors of the enzyme acetylcholinesterease (AChE). Thus, out of a set of 33 synthesised derivatives, several of them were mixed type inhibitors for AChE (from electric eel). Thus, (E)-3-(2,4-dimethoxyphenyl)acrylic anhydride (2c) showed Ki = 8.30 ± 0.94 μM and Ki′ = 9.54 ± 0.38 μM, and for (E)-3-(3-chlorophenyl)acrylic anhydride (2u) Ki = 8.23 ± 0.93 μM and Ki′ = 13.07 ± 0.46 μM were measured. While being not cytotoxic to many human cell lines, these compounds showed an unprecedented and noteworthy inhibitory effect for AChE but not for butyrylcholinesterase (BChE).

One-pot synthesis of cinnamic anhydrides from cinnamic acids and 6-chloro-2,4-dimethoxy-sec-triazine (CDMT) at room temperature

Symmetric cinnamic anhydrides were prepared by the reactions of cinnamic acid substrates with 6-chloro-2,4-dimethoxy-sec-triazine. The reactions were performed at room temperature for 15 h. Diverse cinnamic acid substrates bearing electron-withdrawing or -donating groups worked well, providing the corresponding cinnamic anhydrides in moderate-to-good yields.

Photocatalytic Systems with Flavinium Salts: From Photolyase Models to Synthetic Tool for Cyclobutane Ring Opening

Two new photocatalytic systems based on flavinium species formed in situ by protonation of riboflavin-tetraacetate (1) with triflic acid or prepared in advance via alloxazine quaternization are presented as effective tools for oxidative cyclobutane ring [2 + 2] cycloreversion using visible light. The system with 1,3-dimethyl-8-trifluoromethylalloxazinium perchlorate (2c) was found to be superior allowing an acid-free mild procedure, which results in the opening of cyclobutanes with high oxidation potential (up to 2.14 V) and/or with sensitive groups (e.g., furan) without side reactions.

Novel enzymatic synthesis of 4-O-cinnamoyl quinic and shikimic acid derivatives

The first direct synthesis of 4-O-cinnamoyl derivatives of quinic and shikimic acids were accomplished by regioselective esterification with Candida antarctica lipase A. For hydrocinnamic esters, enzymatic transesterification with vinyl esters gave excell

Preparation of S-2-ethylhexyl-para-methoxycinnamate by lipase catalyzed sequential kinetic resolution

S-2-Ethylhexyl-para-methoxycinnamate S-6 is prepared by a sequential biocatalytic resolution. First, either enantioselective acetylation of rac 2-ethylhexanol (±)-1- by vinylacetate to R-(-)-2-ethylhexylacetate R-2, or alcoholysis of rac 2-ethylhexylbutyrate (±)-3 by n-butanol to S-(+)-2-ethylhexanol S-1 is completed, than, without isolation of the enantiomerically enreached S-alcohol, its enantioselective acylation with the activated para-methoxycinnamic acid derivatives 4,5 is performed, both steps being catalyzed by different microbial lipases. The highest amplification of enantioselectivity is obtained by combining acetylation of rac 2-ethylhexanol catalyzed by Penicillium camembertii lipase or alcoholysis of rac 2-ethylhexylbutyrate catalyzed by Pseudomonas species lipase in the first step, with acylation of enantiomerically enreached S-1 by vinyl-para-methoxycinnamate 4 catalyzed by Lipozyme IM lipase; 84.5% e.e. of S-6 is achieved in the first, and 88% e.e. in the second approach. Since the R-enantiomer of 2-ethylhexanol represents potential source of teratogenic R-2-ethylhexanoic acid, S-6 is regarded as biologically safer UV filter as compared to racemic 2-ethylhexyl-para-methoxycinnamate.