The reaction o f 1-hydroxyxanthenone (1) and hydroxyquinoline (10, 13) Mannich bases with the reactive phosphacumulated ylides (2), represents a new way for the synthesis o f the pyranones and pyranthiones (5, 11, 14). On the other hand, the stabilized phosphorus ylides (6) affect the transylidation o f the Mannich base (1) to the corresponding phosphoranylidenes (9). The structure o f the resu...

An organocatalytic strategy for the synthesis of tetrasubstituted pyrrolidines with monoactivated azomethine ylides in high enantiomeric excess and excellent exo/endo selectivity is presented. The key to success is the intramolecular activation via hydrogen bonding through an o-hydroxy group, which allows the dipolar cycloaddition to take place in the presence of azomethine ylides bearing only ...

The aerobic direct dehydrogenative annulation of N-iminopyridinium ylides with terminal alkynes leading to pyrazolo[1,5-a]pyridine derivatives has been developed.

The application of imidazolinium and amidinium salts as soft Lewis acid organocatalysts is described. These salts were suitable catalysts for the activation of unsaturated thioesters in a Diels-Alder reaction and in the ring opening of thiiranes and epoxides. The products were isolated in good yields. The mild catalysts did not cause desulfurization of the products containing a thiol or thiocar...

The nucleophilic addition of thiocarbamate imidazolium ylide to aldehyde triggered sequential intramolecular N to O migration of thiocarbonyl amide group and reversible oxygen-sulfur rearrangement to afford 2-imidazolium alkylcarbamothioate. The ortho group on phenyl of aldehyde strongly affects the balance of the O- to S-rearrangement.

In this paper, we report DNA and 2'-OMe-RNA probes containing 5-methyl-2-thiocytidine (m(5)s(2)C) residues that can bind selectively and strongly to the corresponding RNA targets containing inosine residues by the significant stacking effect and steric hindrance of the 2-thiocarbonyl group.

Pseudo-C2-symmetric chiral phosphorus ylides have been designed and synthesized for the enantioselective preparation of allenic esters, and up to 92% ee has been achieved.

A heating-induced desulfurization annulation of readily available CF3-imidoyl sulfoxonium ylides and isothiocyanates for the construction 2-trifluoromethylquinolines has been achieved. The developed transformation was performed under metal- additive-free conditions, producing a variety biologically valuable 2-trifluoromethylquinoline derivatives with high efficiency.

A novel copper-catalyzed oxidative desulfurization reaction of thiocarbonyl compounds, using molecular oxygen as an oxidant and leading to formation of carbonyl compounds, has been developed, and the utility of the process is demonstrated by its application to the preparation of a carbonyl-18O labeled sialic acid derivative.