Cinnamic esters synthesis

An interesting footnote to the general synthesis of macrocyclic crown ether-type esters is found in the work of Ors and Srinivasan . These workers used cinnamate esters and diesters as precursors to large ring lactones. Depending on orientation, either truxil-... 

The asymmetric epoxidation of electron-poor cinnamate ester derivatives was highlighted by Jacobsen in the synthesis of the Taxol side-chain. Asymmetric epoxidation of ethyl cinnamate provided the desired epoxide in 96% ee and in 56% yield. Epoxide ring opening with ammonia followed by saponification and protection provided the Taxol side-chain 46 (Scheme 1.4.12). 

This version of the Wadsworth-Emmons reaction has been used in the scaled-up syntheses of drugs and drug-candidate molecules. For example, it is used to prepare a cinnamate ester that is a starting material for pilot plant synthesis of a potential integrin antagonist.263... 

One-pot synthesis of cinnamic esters from methyl phenyisulphinyl-acetate (PhS0CH2C02Me)... 

The Heck reaction on polymer-bound iodoarenes is assisted by the addition of a catalytic amount of tetra-n-butylammonium bromide and has been employed in the synthesis of 4-carboxycinnamic esters and amides [33], and 4-aminosulphonyl-cinnamic esters [34], It has also been reported that the presence of an equimolar equivalent of benzyltriethylammonium chloride aids the Pd(II)-mediated reaction of A -acyl-2-iodoanilines with vinylidene carbonate, which leads to A -acyl-2-hydroxy-indolines providing a convenient route to the indoles (80-90%) [35], The catalysed reaction of 2-hydroxy- and 2-tosylaminoiodobenzene with 1,2-dienes produces 1,2-dihydrobenzofurans and 1,2-dihydroindoles, respectively [36]. 

Accordingly, the synthesis of novel cinnamate polymers with high functionality and performance is very important from the viewpoint of both polymer chemistry and practical use. Recently, we have reported the synthesis of polymers with pendant photosensitive moieties such as cinnamic ester and suitable photosensitizer groups by radical copolymerizations of 2-(cinnamoyloxy) ethyl methacrylate with photosensitizer monomers (9), by copolymerizations of chloromethylated styrene with the photosensitizer monomers followed by the reactions of the copolymers with salts of... 

This article reports on the synthesis of photosensitive polymers with pendant cinnamic ester moieties and suitable photosensitizer groups by cationic copolymerizations of 2-(cinnamoyloxy)ethyl vinyl ether (CEVE) (12) with other vinyl ethers containing photosensitizer groups, and by cationic polymerization of 2-chloroethyl vinyl ether (CVE) followed by substitution reactions of the resulting poly (2-chloroethyl vinyl ether) (PCVE) with salts of photosensitizer compounds and potassium cinnamate using a phase transfer catalyst in an aprotic polar solvent. The photochemical reactivity of the obtained polymers was also investigated. 

Other preparations of 2-iminothiazolidin-4-ones which are discussed in the review by Brown139 utilize the reactions of thiourea with a-hydroxy acids,146 ethyl diazoacetate,73 glycidic esters,74,147 cinnamic acid,148 unsaturated diacids (fumaric, maleic, and citraconic) or their esters or imides,149-152 and propiolic esters.153,154 There has been considerable controversy in the literature surrounding the propiolic ester synthesis since many workers have proposed that the products are 1,3-thiazines (see Section IV, B, 1). The pertinent papers in this controversy have been summarized by Cain and Warrener.155 Nagase158 has recently settled the argument in favor of the 2-iminothiazolidin-4-... 

A recently published full account of another synthesis [69] of the same alkaloid starting from the /rans-cinnamic ester 264 represented a different approach (ACD -> ACDB) to ( )-lycorine (Scheme 42). An intramolecular Diels-Alder reaction of 264 in o-dichlorobenzene furnished the two diastereomeric lactones 265 (86%) and 266 (5%) involving the endo and exo modes of addition respectively. The transposition of the carbonyl group of 265 to 267 was achieved by reduction with lithium aluminium hydride, followed by treatment of the resulting diol with Fetizon s reagent, which selectively oxidised the less substituted alcohol to give isomeric 5-lactone 267. On exposure to iodine in alkaline medium 267 underwent iodolactonisation to afford the iodo-hydroxy y-lactone 268. The derived tetrahydropyranyl ether... 

It was well known that certain low molecular weight cinnamate esters displayed l.c. properties (5). Thus, the p-methoxycinnamate group was attached to a methacrylate via —(—CH2—CH2—)— spacer group in an attempt to obtain a l.c. monomer. Reaction Scheme I describes the synthesis. 

Emmons-Wadsworth reaction. A (Z)-selective synthesis of cinnamic esters is... 

Synthesis of the isoxazoline library [59] was performed on 2-chlorotritylchloride resin. The resin was loaded with diethylphosphonoacetic acid and the polymer-bound phospho-nate reacted with aldehydes to yield substituted E-cinnamic esters or substituted E-acrylic esters. This was followed by a 1,3-dipolar cyclo-addition with nitrileoxides, synthesized via the method of Mukaiyama and Floshinoc [60] (Fig. 17.18). In this reaction, two regioi-somers are formed, each of which exist in two enantiomeric forms. Table 17.4 shows the building blocks used in the library synthesis. 

Cinnamic esters. The synthesis b COOMe, and BuiAs is catalyzed by Cd (I... 

These parameters were probed in an in-depth study dealing with the epoxidation of cis-cinnamate esters 11, a protocol Jacobsen has used for the enantioselective synthesis of diltiazem (13), a commercial anti-hypertensive agent [94TET4323]. Surprisingly, electronic and steric factors on the phenyl moiety exercise practically no influence on the enantioselectivity (1st step) of the reaction, whereas increasing steric... 

Figure 11.10 Synthesis of a block copolymer capsule containing FegOs nanoparticies. Photolysis of the cinnamic ester groups of PCEMA to cyclobutanes cross-links the polymer. Hydroxylation of the double bonds of the PI units makes the particles water-soluble. Hydrolysis of the fert-butyl acrylate (PEBA) units gives acrylic acid units which bind Fe(II). Oxidation of Fe(II) in base produces Fe20j. (Reproduced with permission from R. S. Underhill and G. Liu, Chem. Mater. 2000,12, 2082.)...

Nowadays, several modifications of the Pictet-Gams reaction exist in the literature, constituting the reaction as the method of choice for the synthesis of isoquinoline frameworks when acid labile substituents are not present in the molecule. Modifications include the use of cinnamic esters, instead of 2-phenyl-2-hydroxy ethanamines, as starting materials... 

Pentose-based trisaccharides to have been reported are 0-a-L-Araf-(1 3)-0-3-D-Xyl2.-( 1 - 4)-D-Xyl (synthesis and its isolation as a 5 (hydroxymethoxy)cinnamate ester from a plant source)/ and 0-a-D-KDO-(2 2)-0-3-D-Rlbf-(l 2)-D-Rib (the... 

Calo, V., Nacci, A., MonopoU, A. et al. (2003) Pd nanoparticles catalyzed stereospecific synthesis of /3-aryl cinnamic esters in ionic liquids. J. Org. Chem., 68, 2929-33. 

Park et al, reported the synthesis and application of terpolymer bearing cyclic carbonate and cinnamoyl groups. The syntheses of photopolymer with pendant cinnamic ester and cyclic carbonate groups was achieved by the addition reaction of poly(glycidyl methacrylate-co-styrene) with CO2 and then with cinnamoyl chloride. Quaternary ammonium salts showed good catalytic activity for this synthesis. Photochemical reaction experiments revealed that terpolymer with cinnamate and cyclic carbonate groups has good photosensitivity, even in the absence of sensitizer. In order to expand the application of the obtained terpolymer, polymer blends with poly(methyl methacrylate) were also prepared. 

Instead of the usual strong and expensive bases, alkali carbonates or hydrogeno-carbonates can be used in Wittig-type reactions. For sonochemical applications, no obvious correlation of the reactivity with their lattice energy appears. The reaction applied to the synthesis of cinnamate esters is reasonably rapid even at room temperature, but sonication does not bring about any change in the isomeric ratio. 

In 2005, a procedure based on the synthesis of isoaurones, which is a metabolite of the fungus Thermomonospora alba, was developed by Merlini and co-workers. A series of isoaurostatins were synthesized by Heck type intramolecular cyclization of cinnamic esters of 2-iodophenols (Scheme 2.23). In antitumor activity tests, the cytotoxic activity of these isoaurones was lower than that of the structurally veiy similar... 

The herbicidal activity of sulfonylureas derived from phenylacetic esters is enhanced when the carboxylate moiety is tied up to form a butyrolactone ring. Extension of this structural modification to weakly herbicidal sulfonylureas derived from cinnamate esters gives vinylogous butyrolactones which display significantly improved efficacy. Structure-activity relationships in these two classes of compounds are discussed along with their synthesis involving a novel benzothiazinone dianion and rf/h9-metallation chemistry. 

Narasimhan, B., Belsare, D., Pharande, D., Mourya, V., 8c Dhake, A. (2004). Esters, amides and substituted derivatives of cinnamic acid synthesis, antimicrobial activity and QSAR investigations. European Journal of Medicinal Chemistry, 39,827. 

Claisen Condensation Reparation of Ethyl Cinnamateand Cinnamic Acid 9-16. Malonic Ester Synthesis—Preparation of Ethyl-n-Butylmalonate... 

Whitcombe, M.J., Gilbert, A., and Mitchell, G.R., Synthesis and photochemistry of side-chain liquid crystal polymers based on cinnamate esters, /. Polym. Sci. Part A Polym. Chem., 30, 1681, 1992. 

Imidazo-fused quinazolines have been prepared from A (allylcarbamoyl)-anthra-nilonitriles by ultrasonically treated BY [449], an approach that has also been used for the synthesis of other anellated heterocycles [450] In addition, BY catalyzed the regioselective cycloaddition of nitrile oxides 308 (Fig. 76) to cinnamic esters 309 to afford predominantly 310 (BY9) [451]. Similar reactions have been investigated employing vinyl pyridines [451,452]. 

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