The enantioselective cycloetherification of substituted keto phenols into their corresponding dihydrobenzofuran derivatives was carried out using hydrogen peroxide and chiral quaternary ammonium iodide in micellar med...The enantioselective cycloetherification of substituted keto phenols into their corresponding dihydrobenzofuran derivatives was carried out using hydrogen peroxide and chiral quaternary ammonium iodide in micellar media. This approach increased the conversion rate of cycloetherification and also widened the scope of this particular reaction for various substituted keto phenols with electron withdrawing as well as electron donating functionalities. The use of a surfactant in the cycloetherification reaction increased the yield of the corresponding enantioselective dihydrobenzofuran four times. The conversion rate of keto phenols into their corresponding dihydrobenzofuran derivatives was proportional to the concentration of the surfactant used in the reaction.展开更多
Many researches are undertaken to develop antibiotics to treat resistant tuberculosis. This review discusses new trends in research undertaken on new antituberculars reported to date, with a particular attention on th...Many researches are undertaken to develop antibiotics to treat resistant tuberculosis. This review discusses new trends in research undertaken on new antituberculars reported to date, with a particular attention on their synthesis and analysis.展开更多
Analogues of endomorphin and tripeptidcs modified at positions 4 and 3,respectively,with various phenylalanine analogues were synthesized and their affinities for opioid receptors were evaluated.Most of the peptides e...Analogues of endomorphin and tripeptidcs modified at positions 4 and 3,respectively,with various phenylalanine analogues were synthesized and their affinities for opioid receptors were evaluated.Most of the peptides exhibited potentμ-receptor affinity and selectivity,among them,compound 7（Dmt-Pro-Tmp-Tmp-NH_2） exhibited potent affinity for bothμ-andδ-receptors （K_iμ= 0.47 nmol/L,K_iδ= 1.63 nmol/L）.展开更多
基金Supported by the Rhodes University Joint Research Committee (JRC,grant number 35047)
文摘The enantioselective cycloetherification of substituted keto phenols into their corresponding dihydrobenzofuran derivatives was carried out using hydrogen peroxide and chiral quaternary ammonium iodide in micellar media. This approach increased the conversion rate of cycloetherification and also widened the scope of this particular reaction for various substituted keto phenols with electron withdrawing as well as electron donating functionalities. The use of a surfactant in the cycloetherification reaction increased the yield of the corresponding enantioselective dihydrobenzofuran four times. The conversion rate of keto phenols into their corresponding dihydrobenzofuran derivatives was proportional to the concentration of the surfactant used in the reaction.
文摘Many researches are undertaken to develop antibiotics to treat resistant tuberculosis. This review discusses new trends in research undertaken on new antituberculars reported to date, with a particular attention on their synthesis and analysis.
基金was supported by grants 08KJB350002 and 08NMUZ028in part by the Intramural Research Program of the NIH and NIEHS
文摘Analogues of endomorphin and tripeptidcs modified at positions 4 and 3,respectively,with various phenylalanine analogues were synthesized and their affinities for opioid receptors were evaluated.Most of the peptides exhibited potentμ-receptor affinity and selectivity,among them,compound 7（Dmt-Pro-Tmp-Tmp-NH_2） exhibited potent affinity for bothμ-andδ-receptors （K_iμ= 0.47 nmol/L,K_iδ= 1.63 nmol/L）.
