The coupling of β-hydroxy α-diazocarbonyl compounds with aryl halides is described, which proceeds through a Pd-catalyzed migratory insertion/β-OH elimination sequence. This reaction provides a new route to the synthesis of tetrasubstituted olefins.

Abstract: A rhenium complex, [ReBr(CO)3(thf)]2, catalyzed insertion of terminal alkynes into a C–H bond of active methylene sites of 1,3-dicarbonyl compounds. When a catalytic amount of isocyanide or molecular sieves was added to the reaction mixture, the reaction course changed markedly, and insertion of alkynes into a C–C single bond between αand β-positions of cyclic and acyclic β-keto ester...

Acyclic diazodicarbonyl compounds react at room temperature with cycloaliphatic thioketones, e.g. 2,2,4,4-tetramethyl-3-thioxocyclobutanе-1-one and adamantanethione, via a cascade process in which the key step is a 1,5-electrocyclization of the intermediate thiocarbonyl ylide leading to tetrasubstituted spirocyclic 1,3-oxathioles. The most reactive diazodicarbonyl compound was diazoacetylaceton...

N-Glucuronidation in vitro of six 4-arylalkyl-1H-imidazoles (both enantiomers of medetomidine, detomidine, atipamezole, and two other closely related compounds) by rat, dog, and human liver microsomes and by four expressed human UDP-glucuronosyltransferase isoenzymes was studied. Human liver microsomes formed N-glucuronides of 4-arylalkyl-1H-imidazoles with high activity, with apparent V(max) v...

Urocanic acid (UCA) derivatives were tested for their anti-inflammatory activity in inflammatory bowel disease (IBD) in two models: ex vivo and an experimental mouse model. Ex vivo: inflamed colonic tissue was incubated in culture medium with or without the UCA derivatives. Biopsies, incubated with UCA derivatives, produced lower levels of proinflammatory cytokines IL-6 and IL-8 as compared to ...

The catalytic enantioselective formation of tetrasubstituted α-alkoxycarbonyl compounds is an ongoing challenge to synthetic chemists.[1] Fully-substituted α-hydroxyesters and acids comprise essential components of, and building blocks for, many bioactive natural products. These include quinic acid (1), cytotoxic leiodolide A (2),[2] and the anti-cancer agents in the harringtonine series (3a–f)...

A catalytic method involving carbenoid insertion onto dihydroimidazoles is reported for the generation of dihydroimidazolium ylides, and their subsequent diastereoselective cycloaddition to form pyrrolo[1,2-a]imidazoles © 2009 Elsevier Science. All rights reserved ———

The addition of lithium amides to cyclobutenediones provides access 2-oxo-but-3-enamides and tetrasubstituted furans via a new mode ring opening involving enone cleavage via O- C-lithium transfer.

A novel and straightforward synthetic protocol for the efficient construction of 3',5'-dihydro-1H-spiro[benzo[d]oxepine-2,4'-imidazoles] through a copper(I)-catalyzed reaction between 2-(2-ethynylphenyl)oxirane, sulfonyl azide, and 2-isocyanoacetate is described.