- Synthesis and antifungal activity of cinnamic acid esters
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Cinnamic, p-coumaric and ferulic acids were isolated from pineapple stems (Ananas comosus var. Cayenne). Twenty-four kinds of esters were prepared from these acids, alcohols and the components of Alpinia. Isopropyl 4-hydroxycinnamate (11) and butyl 4-hydroxycinnamate (12) were found to have almost the same effectiveness in antifungal activity against Pythium sp. at l0 ppm as that of the commercial fungicide iprobenfos (Kitazin P).
- Tawata,Taira,Kobamoto,Zhu,Ishihara,Toyama
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- A rapid microwave-assisted esterification utilizing the Mukaiyama supported reagent
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Microwave heating was applied to a modified Mukaiyama reagent supported on a PS-DVB resin to develop a rapid and efficient protocol for the solution-phase synthesis of esters and lactones starting from alcohol and carboxylic acids. The products were obtained in high purity (NMR analysis) after a simple resin filtration.
- Donati, Donato,Morelli, Costanza,Taddei, Maurizio
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- Bioactivity and structure–activity relationship of cinnamic acid derivatives and its heteroaromatic ring analogues as potential high-efficient acaricides against Psoroptes cuniculi
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A series of cinnamic acid derivatives and its heteroaromatic ring analogues were synthesized and evaluated for acaricidal activity in vitro against Psoroptes cuniculi, a mange mite. Among them, eight compounds showed the higher activity with median lethal concentrations (LC50) of 0.36–1.07 mM (60.4–192.1 μg/mL) and great potential for the development of novel acaricidal agent. Compound 40 showed both the lowest LC50 value of 0.36 mM (60.4 μg/mL) and the smallest median lethal time (LT50) of 2.6 h at 4.5 mM, comparable with ivermectin [LC50 = 0.28 mM (247.4 μg/mL), LT50 = 8.9 h], an acaricidal drug standard. SAR analysis showed that the carbonyl group is crucial for the activity. The type and chain length of the alkoxy in the ester moiety and the steric hindrance near the ester group significantly influence the activity. The esters were more active than the corresponding thiol esters, amides, ketones or acids. Replacement of the phenyl group of cinnamic esters with α-pyridyl or α-furanyl significantly increase the activity. Thus, a series of cinnamic esters and its heteroaromatic ring analogues with excellent acaricidal activity emerged.
- Chen, Dong-Dong,Zhang, Bing-Yu,Liu, Xiu-Xiu,Li, Xing-Qiang,Yang, Xin-Juan,Zhou, Le
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supporting information
p. 1149 - 1153
(2018/03/05)
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- N-heterocyclic carbene-catalyzed oxidative esterification reaction of aldehydes with alkyl halides under aerobic conditions
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An efficient N-heterocyclic carbene-catalyzed oxidative esterification reaction of aldehydes with alkyl halides or alkyl 4-methylbenzenesulfonate is reported. It was worth noting that (1) the configuration of alkyl halides or alkyl 4-methylbenzenesulfonates was inverted completely, and (2) the presence of oxygen was crucial for this transformation. The reaction proceeded smoothly under mild conditions and various esters were afforded in moderate to good yields. In addition, we have developed an efficient tandem oxidation/ esterification reaction of alcohols. This methodology provides a rare example of a reaction of the Breslow intermediate to sp3-carbon centered electrophiles. An efficient oxidative esterification reaction of aldehydes with alkyl halides or alkyl 4-methylbenzenesulfonates catalyzed by N-heterocyclic carbenes is reported. Oxygenwas crucial for the reaction, and the configuration of alkyl 4-methylbenzenesulfonate was completely inverted. Copyright
- Xin, Yang-Chun,Shi, Shi-Hui,Xie, Dong-Dong,Hui, Xin-Ping,Xu, Peng-Fei
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supporting information; experimental part
p. 6527 - 6531
(2011/12/22)
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