Selenonium ylides: synthesis, characterization, and applications to photo-induced cyclopropanation reactions

Abstract

Carbenes are important and highly reactive intermediates for the synthesis of various complex molecules. They are now an indispensable chemical species in organic chemistry and are used frequently to synthesize complex compounds in drug discovery chemistry. In general, carbenes are synthesized by a combination of transition metal catalysts and diazo compounds or by the decomposition reactions of diazo compounds. This paper reports the development of the visible light for the photochemical generation of carbenes from a novel C,Se-selenonium ylide. Overall, this photochemical carbene generation method using C,Se-selenonium ylide does not require a catalyst, is simple to perform, and enables highly efficient cyclopropanation reactions with alkenes.

Visible photons as ideal reagents for the activation of coloured organic compounds

“…The resulting disubstituted carbene led to cyclopropanes 71.9a-c by reaction with electron-rich (71.8a, b) and electron-poor (71.8c) olefins. 242 Scheme 68 Synthesis of sulfilimines and allylic sulfenamides. The reactivity of the carbenes is so high that even a CQC bond included in a (hetero)aromatic ring may be used for the construction of a three-membered ring.…”

Synthetic application of chalcogenonium salts: beyond sulfonium

“…Reactions conducted in the presence of excess alkenes lead to cyclopropane derivatives in a sensitizer-and photocatalyst-free fashion. 38 The application of telluronium ylides in organic transformations has appeared in a few reports in the literature since the publication of the last review article 39 and the outstanding contributions of Tang's group on the subject. 36a,b For instance, Huang et al reported the use of a stoichiometric amount of telluronium salt 51 to convert aromatic aldehydes to the corresponding epoxides 52 in high yields with excellent diastereo-and enantioselective upon treatment with NaOH (Scheme 22).…”

“…Reactions conducted in the presence of excess alkenes lead to cyclopropane derivatives in a sensitizer- and photocatalyst-free fashion. 38…”

Visible Light‐Mediated Cyclopropanation: Recent Progress

“…In addition to iodonium ylides, selenonium ylides were recently reported by Itoh as acceptor/acceptor type carbenes precursors under the irradiation with 400 nm blue LED to achieve the cyclopropanation of alkenes (Scheme 15). [42] …”