Acyl radicals generated by the addition of alkyl or vinyl radicals to carbon monoxide cyclized onto the C-N bonds of imines and oxazoline with perfect 6-endo selectivity, driven by a preference for attack at nitrogen.
The Mizoroki-Heck reaction was carried out using a fluorous ether F-626 as the solvent and a fluorous Pd carbene complex as the catalyst. When carboxylic acids are the products, separation of both the F-626 and the Pd catalyst from the products can be conveniently carried out by simple filtration. The F-626 filtrates containing the Pd catalyst can be recycled.
Deprotonierung und Sn/Li‐Austausch ermöglichen die Umwandlung der Ketone 1 in die Titelverbindungen 2 , die sich als äußerst nützliche Synthesezwischenstufen erwiesen haben. Sie reagieren als α,β‐Dianionen von Ketonen mit Elektrophilen, wobei nacheinander mit zwei verschiedenen Elektrophilen umgesetzt werden kann. magnified image
Kinetically controlled Fischer glycosidation was achieved under flow conditions. β-Hydroxy-substituted sulfonic acid functionalized silica (HO-SAS) was used as an acid catalyst. This reaction directly converted aldohexoses into kinetically favored furanosides to enable the practical synthesis of furanosides. After optimization of the reaction temperature and residence time, glucofuranosides, galactofuranosides, and mannofuranosides were synthesized in good yields.
The first Pd-catalyzed carbonylative couplings of aryl and vinyl halides with vinylogous enolates are reported generating products derived from C-C bond formation exclusively at the γ-position. Good results were obtained with a dienolate derivative of acetoacetate (1,3-dioxin-4-one). These transformations occurred at room temperature and importantly with only stoichiometric carbon monoxide in a two-chamber reactor. The methodology was applied to the synthesis of two members of the statin family generating the cis-3,5-diol acid motif by a γ-selective carbonylation followed by a cis-stereoselective reduction of the 3,5-dicarbonyl acid intermediates.
Immer flexibel bleiben: Ein Mikroreaktor bestehend aus flexiblem Polyimidfilm wurde entwickelt. Er ist leichter herzustellen als Glas-Mikroreaktoren und, anders als andere Polymermikroreaktoren, inert gegen Lösungsmittel und Säuren bei drastischen Bedingungen. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
1 atm CO, 30°C und 10 Mol‐% Selen , das sind die Bedingungen, unter denen gemäß Gleichung (a) die S ‐Alkylthiocarbamate 1 in 41–100% Ausbeute erhalten werden. Als Zwischenstufen sind Selenocarbamate, Carbonylselenid und Carbonylsulfid anzunehmen. R 1 ,R 2 = Et, n Pr, n Bu, Ph, H; R 3 = Me, Et, PhCH 2 , 4‐ClC 6 H 4 CH 2 . magnified image
