Asymmetric transformations from sulfoxonium ylides

Abstract

Sulfoxonium ylides are important surrogates of diazo compounds and its use in industry as safer alternatives has been evaluated during several years. Beyond classical transformations these ylides have also surprised...

Ruthenium(ii)-catalyzed synthesis of CF3-isoquinolinones via C–H activation/annulation of benzoic acids and CF3-imidoyl sulfoxonium ylides

“…On the basis of the isotope-labeling experiments and literature reports, 11,12 we proposed a plausible catalytic cycle as shown in Scheme 5. Initially, the weak O -coordination of benzoic acid ( 1a ) to the Ru( ii ) catalysis occurs, followed by ortho -C–H activation to generate a five-membered Ru( ii ) species ( I ).…”

“…Acyl sulfoxonium ylides are stable carbene precursors, which are widely used as coupling partners in transition metal-catalyzed C–H alkylation reactions. 9,11 Since we have done some research on sulfoxonium ylide chemistry, 12 we recently synthesized a range of CF 3 -imidoyl sulfoxonium ylides (TFISYs), which could serve as versatile CF 3 -containing building blocks for the construction of highly decorated CF 3 -pyrroles 12a and CF 3 -pyridones. 12b Herein, we propose a Ru( ii )-catalyzed C–H activation/annulation of benzoic acids with TFISYs to obtain a series of 3-CF 3 isoquinolinones, in which the carboxylic acid serves as a weakly coordinating directing group to facilitate the desired ortho -C–H activation (Scheme 1d).…”

Organocatalytic asymmetric azidation of sulfoxonium ylides: mild synthesis of enantioenriched α-azido ketones bearing a labile tertiary stereocenter

“…Recently, α -carbonyl sulfur ylides have been developed as powerful surrogates to α -diazocarbonyl compounds, participating in a range of asymmetric cycloaddition and H–X bond insertion reactions, with the latter still in its infancy. 15–17 The amenability of this chemistry to mild metal-free organocatalytic conditions, combined with our continued interests in this topic, 17 led us to envision that an asymmetric formal H–N 3 insertion of α -carbonyl sulfoxonium ylides could be possibly achieved. 18 If successful, it would not only eliminate the drawback of the already powerful diazo-based carbene insertion chemistry, but also serve as an important alternative solution to the above challenge in the synthesis of enantioenriched α -azido carbonyl compounds (Scheme 1d).…”

The photocatalytic selective 1,2-hydroxyacylmethylation of 1,3-dienes with sulfur ylides as the source of alkyl radicals

“…Utilization of the zwitterionic properties of sulfur ylides has long been known as a versatile strategy in a wide range of chemical transformations for the construction of different-sized rings. 1 Some of these thermal reactions have also become common knowledge and are found in textbooks. In comparison to their use in ionic chemistry, the use of sulfur ylides in radical synthetic chemistry has been significantly limited due to a dearth of general activation methods despite the direct photolysis of sulfur ylides 2 and theoretical studies 3 on sulfur ylide radical cations being the subject of study for more than five decades.…”