Search PubMed⌕ Search

PubMed · 11842425

Solid phase chemical technologies for combinatorial chemistry.

Abstract

This article describes the exploration of synthetic methodologies on solid phase for combinatorial chemistry. Examples will cover various cyclisation strategies that include; the intramolecular Heck cyclisation leading to the formation of oxindoles, the radical cyclisation mechanism in the synthesis of furans, and a stereoselective cyclisation to form oxopiperazines.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S Balasubramanian. 2001. Solid phase chemical technologies for combinatorial chemistry.. https://doi.org/10.1002/jcb.10063

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Dioxins in commercial United States baby food.

This is the first known study of dioxins, dibenzofurans, and polychlorinated biphenyls (PCBs) in commercial American bottled baby foods purchased in the United States. Dioxins, persistent chlorinated organics, are inadvertent by-products of chemical synthesis or combustion and are toxic to humans and other animals. Almost all dioxins enter the body through food consumption, specifically from food products containing animal fat. Major-brand bottled baby food containing meat was purchased at U.S. supermarkets and 12 pooled samples were analyzed for dioxins using high-resolution gas chromatography with high-resolution mass spectrometry. Low levels of dioxins were found in these products. The range was from 28 to 226 parts per quadrillion (ppq) dioxin toxic equivalents (TEQ). This is reported on a whole or wet weight (as eaten) basis. As a comparison, findings of dioxins in U.S. supermarket meat ranged from 28 to 540 ppq. Although dioxin levels are generally lower in these baby foods than in meat or poultry, the presence of dioxins in commercial baby food containing meat is cause for concern.

Benzofurans↗

Singlet oxygen trapping by DRD156 in micellar solutions.

Recently, 4.4'-bis(1-p-carboxyphenyl-3-methyl-5-dydroxyl)-pyrazol (DRD156) has been developed as a new sensitive reagent that reacts specifically with singlet oxygen. The specificity of DRD156 for singlet oxygen in a biomimetic solution (micellar solution) and the effects of its coexistence with other reagent were examined with electron spin resonance (ESR). Singlet oxygen was generated using photosensitization reaction. The ESR spectrum of the radical derived from DRD156 after the reaction with singlet oxygen in phosphate buffered salines (PBS) was comprised of twenty-nine lines, whereas that in cetyltrimethylammonium bromide (CTAB) micelles was comprised of nine lines. Both 2,2,6,6-tetramethyl-4-piperidine (TMPD) and 1,3-diphenyl-isobenzofuran (DPBF) reduced the singlet oxygen-DRD156 signal intensity, and TMPD-mediated decrease in PBS (to 62%) was almost the same as that in CTAB micelle (to 65%). In contrast, DPBF reduced the DRD156 signal intensity more effectively in CTAB micelle (to 12%) than PBS (to 38%). These results indicate that the specificity of DRD156 for singlet oxygen is dependent on microenvironment.

Benzofurans↗

Micropore-free surface-activated carbon for the analysis of polychlorinated dibenzo-p-dioxins-dibenzofurans and non-ortho-substituted polychlorinated biphenyls in environmental samples.

2,3,7,8-Substituted polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) and non-ortho-substituted polychlorinated biphenyls (PCBs) account for almost all of the total toxic equivalents (TEQ) in environmental samples. Activated carbon columns are used to fractionate the samples for GC-MS analysis or bioassay. Micropore-free surface-activated carbon is highly selective for PCDD/Fs and non-ortho-PCBs and can improve the conventional activated carbon column clean-up. Along with sulfuric acid-coated diatomaceous earth columns, micropore-free surface-activated carbon provides a rapid, robust, and high-throughput sample preparation method for PCDD/Fs and non-ortho-PCBs analysis.

Benzofurans↗