Regio-selective syntheses of bis(2-haloalkyl) selenides and dihalo[bis(2-haloalkyl)]-λ4-selanes from selenium dihalides and 1-alkenes and the methoxyselenenylation reaction

A Regioselective Synthesis of Novel Functionalized Organochalcogen Compounds by Chalcogenocyclofunctionalization Reactions Based on Chalcogen Halides and Natural Products

“…The isomerization process and intramolecular nucleophilic substitution proceed smoothly at room temperature due to high anchimeric assistance effect of the selenium atom, which activates halogen atoms in β-haloorganyl selenides B ( Scheme 5 ) [ 58 ]. Previously, we observed the formation of anti-Markovnikov adducts in the reactions of selenium dibromide with 1-alkenes and their isomerization into thermodynamically more stable Markovnikov products at room temperature [ 76 , 77 ]. The bromine atom is better leaving group compared to the chlorine atom in nucleophilic substitution and selenium dibromide is more efficient than selenium dichloride in these reactions.…”

Natural Compounds and Their Structural Analogs in Regio- and Stereoselective Synthesis of New Families of Water-Soluble 2H,3H-[1,3]thia- and -Selenazolo[3,2-a]pyridin-4-ium Heterocycles by Annulation Reactions

“…It is known that electrophilic addition of sulfenyl halides to linear 1-alkenes afforded predominantly anti-Markovnikov products [44][45][46][47]. Thiiranium [45][46][47][48] and seleniranium [47][48][49][50][51][52][53][54] cations are often regarded as intermediates in electrophilic addition of chalcogenyl halides to the double bond, and attack of the halide anion occurs at unsubstituted carbon atom of thiiranium or seleniranium cations leading to Suggested reactions pathways can be regarded on the examples of reactions of 2-pyridinechalcogenyl halides with styrene and allylbenzene (Scheme 6). The reactions of 2-pyridinesulfenyl and selenenyl halides with compounds containing a double bond conjugated with the benzene ring (isoeugenol, methyl isoeugenol, trans-anethole, styrene, 4-methylstyrene, α-methylstyrene) proceed regioselectively via electrophilic addition of the chalcogen atom at β-carbon atom of the double bond.…”

“…It is known that electrophilic addition of sulfenyl halides to linear 1-alkenes afforded predominantly anti-Markovnikov products [44][45][46][47]. Thiiranium [45][46][47][48] and seleniranium [47][48][49][50][51][52][53][54] cations are often regarded as intermediates in electrophilic addition of chalcogenyl halides to the double bond, and attack of the halide anion occurs at unsubstituted carbon atom of thiiranium or seleniranium cations leading to In the case of eugenol, its derivatives and structural analogs, 2-pyridinesulfenyl and selenenyl halides react with allyl group as with linear 1-alkene and electrophilic addition of the chalcogen atom occurs at α-carbon atom of the double bond (C and D are possible intermediates in the reaction of 2-pyridinesulfenyl chloride with allylbenzene) followed by intramolecular nucleophilic substitution in the formed anti-Markovnikov adduct (Scheme 6). It is known that electrophilic addition of sulfenyl halides to linear 1-alkenes afforded predominantly anti-Markovnikov products [44][45][46][47].…”

“…Thiiranium [45][46][47][48] and seleniranium [47][48][49][50][51][52][53][54] cations are often regarded as intermediates in electrophilic addition of chalcogenyl halides to the double bond, and attack of the halide anion occurs at unsubstituted carbon atom of thiiranium or seleniranium cations leading to anti-Markovnikov products. Besides, the formation of thiiranium and seleniranium species determines the reaction course as anti-addition in reactions of sulfenyl and selenenyl halides with alkenes.…”

Efficient Synthesis of a New Family of 2,6-Disulfanyl-9-selenabicyclo[3.3.1]nonanes

“…Annulation reactions of selenium dihalides with unsaturated arenes gave various condensed heterocyclic compounds [ 40 , 41 , 42 , 43 , 44 ]. The addition of selenium dihalides to alkenes and alkynes afforded bis(2-haloalkyl) selenides [ 45 , 46 ] and bis(2-halovinyl) selenides in high yields [ 47 , 48 , 49 , 50 , 51 , 52 ]. Novel heterocycles [ 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ] have been obtained by reactions of selenium dihalides with divinyl chalcogenides [ 63 , 64 , 65 ].…”