Isothiourea HBTM-2.1 catalyzes the asymmetric Michael addition/lactonization of aryl- and alkenylacetic acids using α-keto-β,γ-unsaturated phosphonates as α,β-unsaturated ester surrogates, giving access to a diverse range of stereodefined lactones or enantioenriched functionalized diesters upon ring-opening.

Acrylic esters, thioesters and N-acryloyl pyrrole have been identified as effective electrophiles in the enantioselective Michael addition reaction with beta-keto ester pro-nucleophiles catalysed by a cinchona alkaloid derived bifunctional organocatalyst; enantiomeric excesses of up to 98% and yields of up to 96% can be obtained for a range of Michael acceptors and pro-nucleophiles.

FeCl3.6H2O was used as an efficient catalyst for the synthesis of highly functionalized piperidines via a one-pot five-component reaction of aromatic amines, aromatic aldehydes and β-keto esters in EtOH at room temperature. The remarkable advantages offered by this method are good yields, simple procedure, short reaction times, no need to column chromatography and easy work-up. The structures o...

Room temperature, light induced (P700(+)-P700) Fourier transform infrared (FTIR) difference spectra have been obtained using photosystem I (PS I) particles from Synechocystis sp. PCC 6803 that are unlabeled, uniformly (2)H labeled, and uniformly (15)N labeled. Spectra were also obtained for PS I particles that had been extensively washed and incubated in D(2)O. Previously, we have found that ex...

The specific mechanisms by which skin blood flow increases in response to a rise in core body temperature via cutaneous active vasodilation are poorly understood. The primary purpose of this study was to determine whether the cyclooxygenase (COX) pathway contributes to active vasodilation during whole body heat stress (protocol 1; n = 9). A secondary goal was to verify that the COX pathway does...

A new one-pot approach for the synthesis of aryl a-keto ester based on the diazo transfer and oxidation of diazo group is developed. 2005 Elsevier Ltd. All rights reserved. 1 3 Ar OMe O [O] Ar OMe O O Ar OMe N2 [O] Base ArSO2N3 a-Keto acids and esters have been important compounds as natural products and as the building blocks in organic synthesis. Over the past decades, various methods have be...

Chlorophyll-a plays a fundamental role in the solar energy conversion processes that occur in oxygen evolving organisms, such as plants algae and cyanobacteria. To study the chlorophyll-a species at the heart of these solar conversion processes FTIR difference spectroscopy has been a valuable tool. However, FTIR difference spectra are only partially understood. To gain a more detailed understan...

We have previously shown that plasma high density lipoproteins (HDL) stimulate release of prostacyclin, measured as its stable metabolite, 6-keto-PGF1 alpha, by cultured porcine aortic endothelial cells. The present experiments were designed to elucidate the contribution of HDL lipids to endothelial cellular phospholipid pools and to prostacyclin synthesis. In experiments with reconstituted HDL...