Abstract Ruthenium‐catalyzed C−H bond activation and tandem cyclization of 2‐arylimidazo[1,2‐ a ]pyridines with iodonium ylides proceed efficiently. For the first time, easily available inexpensive ruthenium complex were employed to synthesize pyrido[1,2‐ ]benzimidazole derivatives in good yields under simple easy‐to‐operate conditions. Several primary mechanism investigations synthetic applica...

The 3-azabicycloACHTUNGTRENNUNG[3.1.0]hexane is a common motif in natural products. Furthermore this rigid framework represents a privileged class of pharmacologically active compounds, often showing enhanced binding affinities with their targets (Figure 1). These bicycles also represent conformationally restricted analogues of piperidines (e.g. trovafloxacin). When substituted with a carboxyli...

The one-carbon ring expansion of 1-deoxy-1-thio-1,6-anhydrosugars, mediated by metal carbenes and proceeding through the intermediacy of sulfur ylides, has been proposed as a route for the synthesis of the tagetitoxin skeleton. Intermolecular reactions of such thioanhydrosugars with diazoesters afford a range of undesired products derived from the initially formed ylide, whereas use of an intra...

A new reaction for the rhodium-catalyzed geminal-difunctionalization-based fluorination is presented. The substrates are aromatic and aliphatic diazocarbonyl compounds. As the fluorine source a stable and easily accessible benziodoxole reagent was used. A variety of alcohol, phenol, and carboxylic acid reagents were employed to introduce the second functionality. The reaction was extended to tr...

A domino sequence has been developed between vinyldiazoacetates and racemic allyl alcohols, involving five distinct steps. The sequence generates highly functionalized cyclopentanes with four new stereogenic centers as single diastereomers in 64-92% ee. The first step is a rhodium-catalyzed oxygen ylide formation, which is then followed by a [2,3]-sigmatropic rearrangement, an oxy-Cope rearrang...

The highly efficient asymmetric epoxidation of aldehydes by methylene transfer is now possible using new sulfonium salts.

The mechanism of the Wittig reaction of anisaldehyde with a stabilized ylide was studied by a combination of (13)C kinetic isotope effects, conventional calculations, and molecular dynamics calculations in a cluster of 53 THF molecules. The isotope effects support a cycloaddition mechanism involving two sequential transition states associated with separate C-C and P-O bond formations. However, ...