Phenyl alkynyl selenides

Alkynyl(phenyl)iodonium salts have found synthetic application for the preparation of various substituted alkynes by the reaction with appropriate nucleophiles, such as enolate anions [980,981], selenide and telluride anions [982-984], dialkylphosphonate anions [985], benzotriazolate anion [986], imidazolate anion [987], N-functionalized amide anions [988-990] and transition metal complexes [991-993]. Scheme 3.291 shows several representative reactions the preparation of Ai-alkynyl carbamates 733 by alkynylation of carbamates 732 using alkynyliodonium triflates 731 [989], synthesis of ynamides 735 by the alkyny-lation/desilylation of tosylanilides 734 using trimethylsilylethynyl(phenyl)iodonium triflate [990] and the preparation of Ir(III) a-acetylide complex 737 by the alkynylation of Vaska s complex 736 [991]. 

Recent examples of the rearrangement or alkynylation pathway include conversions of arylethynyl- and er -butylethynyl(phenyl)iodonium tosylates 24 and 25 to alkynylphosphonates, -selenides, and -tellurides with the appropriate anion salts in DMF (Scheme 50) [145-147], and a similar synthesis of push-pull selenides and tellurides from alkynyliodonium triflates containing electron-withdrawing groups in the alkynyl moiety [148]. 

Terminal alkynes reacted in a different way with DIB and diphenyl diselenide, yielding phenyl alkynyl selenides in varying yield, from 81%, for phenylselenyl phenylacetylene, to 15% for trimethylsilyl phenylselenyl acetylene. It is noteworthy... 

Phenyl alkynyl selenides. Phenylselenylation of 1-alkynes is easily accomplished with the PhI(OAc)z-PhSeSePh combination. 

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