Stereoselective synthesis of vinylic selenides

Hydrotelluration of alkynes: a unique route to Z-vinyl organometallics

“…No isomerization of the products of the hydrotelluration of alkynes was reported to date. The hydrotelluration is similar to the hydroselenation 9 in terms of the steric course, but differs in the stability of the products. Vinylic selenides isomerize easily, giving mixtures of Z and E olefins 10 , what is opposed to the stereochemical stability of the tellurides.…”

“…In some cases the exclusive formation of one of the possible isomers was observed. The following heterocyclic systems were formed: 3-benzotellurepine (1) 14a , 1-benzotellurepine (2) 14b-d , tellurochromenes (3) 14b , benzotellurophenes (4 14e , 5 14f ), tellurophthalides (6) 14g , tellurochromones (7) 14h , iso-tellurochromenes (8) 14i,g , telluroindanes (9) 14i,j and benzotellurazepines (10) 14l (Scheme 12). .…”

A facile stereoselective synthesis of (E)‐1,2‐disubstituted vinylic selenides via hydromagnesiation of alkylarylacetylenes

“…Due to their synthetic utility, a variety of methods have been developed for their stereoselective preparation including those involving the addition of selenophenol to acetylenes [3], the radical hydroselenation of alkynes with triorganoselenoboranes [4], the reduction of acetylenic selenides with LiAlH 4 [5], and zirconium-selenium transmetalation [6]. Recently, Huang and Zhu have reported the stereoselective synthesis of (E)-vinylic selenides via hydrozirconation of arylselenoethynes followed by the cross coupling reaction with aryl halides in the presence of Pd(PPh 3 ) 4 [7].…”

Copper‐catalyzed cross‐coupling of α ‐seleno‐acylzirconocene chloride with haloalkynes: Synthesis of α ‐seleno‐substituted vinyl alkynyl ketones

“…Zirconium hydride Cp 2 Zr(H)Cl and internal alkylselenoacetylenes were prepared according to the methods described previously in the literature, Refs. [13] and [14], respectively.…”