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Both RhH(CO)PPh3)3 and a catalyst made in situ from RhCl3·3H2O, PPh3 and Na2CO3 catalyse the reaction of a range of aldehydes with simple primary alcohols to give esters together with alcohols formed by reduction of the aldehydes. The proportion of ester can be increased by adding an efficient hydrogen acceptor. The reaction can also be used to produce 5- and 7-membered lactones from aromatic dialdehydes. Propan-2-ol and the in situ catalyst reduce some aromatic aldehydes to the corresponding alcohols without concomitant ester formation. 相似文献
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Ronald Grigg Thomas R.B. Mitchell Somyote Sutthivaiyakit Ngampong Tongpenyai 《Tetrahedron letters》1981,22(41):4107-4110
Selective catalytic monoalkylation of arylacetonitriles by primary alcohols can be achieved at ≤ 100° using a catalyst prepared in situ from rhodium trichloride, triphenylphosphine and sodium carbonate. RuH2(PPh3)4 is a more effective catalyst for this process. 相似文献
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Chusaksri S Sutthivaiyakit S Sutthivaiyakit P 《Analytical and bioanalytical chemistry》2006,384(5):1236-1245
A confirmatory method for the determination of organochlorine pesticides (OCPs) and their metabolites (endrin, α-endosulfan,
β-endosulfan, endosulfan sulfate, heptachlor, heptachlor epoxide, 2,4′-DDD, 4,4′-DDD, 2,4′-DDE 4,4′-DDE, 2,4′-DDT, and 4,4′-DDT)
in surface waters using liquid chromatography /APCI/tandem mass spectrometry has been developed. Chromatographic separation
was carried out on a ChromSpher 5 Pesticide column using a gradient elution with mobile phase 1mM ammonium acetate-acetonitrile.
Endrin, α-endosulfan, β-endosulfan , endosulfan sulfate, heptachlor and heptachlor epoxide were determined in the negative
ionization mode, while the rest compounds in positive ionization mode. For the identification of the analytes, two multireaction
monitoring transitions were selected per compounds except for the heptachlor which selected ion monitoring was used. The linearity
of the optimized method ranges after SPE concentration, from 0.009 to 30.60 μgL−1 with correlation coefficients greater than 0.99. The method recovery values varied from 72 to 119 % for the different fortification
levels . The developed method was successfully applied to determine OCPs and their metabolites in surface water samples collected
near paddy fields in growing season of rice, at year 2005 in Pathumthani province, Thailand. Endosulfan sulfate was detected
in five out of seven samples and three of them could be quantitated in the range of 0.31to 0.50 μgL−1. 相似文献
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Somyote Sutthivaiyakit Chonticha Seeka Thanasarn Kritwinyu Somchai Pisutchareonpong Nittirat Chimnoi 《Tetrahedron letters》2012,53(14):1713-1716
Four new triterpenes, 2α,3β-dihydroxy-19-nor-11-oxo-20-dimethylurs-12-en-24,28-dioic acid (equivalent to 2α,3β-dihydroxy-19-nor-11-oxoolean-12-en-24,28-dioic acid), 2α,3β-dihydroxy-18,19-seco-19-oxours-11,13(18)-dien-24,28-dioic acid, 2α,3β,19α-trihydroxy-11-oxours-12-en-24,28-dioic acid and 2α,3β,19α-trihydroxy-28-1′-β-d-[glucopyranosyl-(1″→6′)-glucopyranosyl]-urs-12-en-24,28-dioic acid were isolated from the methanol extract of the bark of Diospyros decandra as their acetate-methyl ester derivatives. The first two compounds represent the biosynthetic transformation products of 2α,3β,19-trihydroxyurs-24,28-dioic acid via oxidative rearrangement of ring E. 相似文献
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5-Methylene-2-(2′ -thiazolylazo)-anisole can be immobilized on silica via a SiOSiC moiety. Distribution coefficient studies of platinum metals, gold and base metals show that the chelating silica is selective for palladium(II). The chelating silica is used to preconcentrate and separate palladium from synthetic solution containing traces of palladium and large amounts of copper. The capacity for palladium is about 0.07 mmol g?1. 相似文献
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Somyote Sutthivaiyakit Wantana Mongkolvisut Pongsak PonsitipiboonSamran Prabpai Palangpon KongsaereeSomsak Ruchirawat Chulabhorn Mahidol 《Tetrahedron letters》2003,44(18):3637-3640
Integerrimene, a possible biogenetic precusor of the rhamnofolane diterpenes and a new rhamnofolane endoperoxide 2-epicaniojane together with caniojane and 1,11-bisepicaniojane were isolated from J. integerrima roots. Their structures were elucidated by spectroscopic methods. The X-ray structure of 2-epicaniojane is also presented. 相似文献
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Somyote Sutthivaiyakit Narissara Na NakornWolfgang Kraus Pakawadee Sutthivaiyakit 《Tetrahedron》2003,59(50):9991-9995
An unusual 29-nor-3,4-seco-friedelan-4(23),20(30)-dien-3-oic acid and a new 5-hydroxy-6,9-epoxyguaiane have been isolated along with other rare terpenes and lignans from Phyllanthus oxyphyllus roots. Their structures were elucidated from spectroscopic data. The radical scavenging properties of some of these compounds were evaluated. seco-Isolariciresinol showed strong antioxidant activity (IC50 0.017±0.001 mM). 相似文献
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