TY - JOUR
T1 - Synthesis and reactivity of divinylselenium dichlorides and dibromides
AU - Braverman, Samuel
AU - Pechenick-Azizi, Tatiana
AU - Gottlieb, Hugo E.
AU - Sprecher, Milon
PY - 2011
Y1 - 2011
N2 - Regio- and stereospecific electrophilic addition reactions of selenium tetrachloride and selenium tetrabromide to propargyl alcohols are reported. (Z,Z)-Bis(β-chlorovinyl)selenium dichlorides were isolated in high yields, and their reactivity was dependent on their substitution pattern. Products derived from unsubstituted, α-methyl-, or α, α- dimethylpropargyl alcohols readily underwent transfer of chlorine atoms to one of the two double bonds. (Z,Z)-Bis(β-chlorovinyl)selenium dichlorides derived from γ-phenyl- or γ-isopropenylpropargyl alcohols underwent cyclization to form benzoselenophene derivatives; this was accompanied by the formation of the corresponding dichloro-substituted allylic alcohols. In contrast, selenium tetrachloride reacts with γ-phenylpropargyl alcohol exclusively as a chlorinating agent, giving (3-chloroprop-1-yn-1-yl)benzene quantitatively. Products of regio- and stereospecific electrophilic addition of selenium tetrabromide are also described. Reaction mechanisms are proposed.
AB - Regio- and stereospecific electrophilic addition reactions of selenium tetrachloride and selenium tetrabromide to propargyl alcohols are reported. (Z,Z)-Bis(β-chlorovinyl)selenium dichlorides were isolated in high yields, and their reactivity was dependent on their substitution pattern. Products derived from unsubstituted, α-methyl-, or α, α- dimethylpropargyl alcohols readily underwent transfer of chlorine atoms to one of the two double bonds. (Z,Z)-Bis(β-chlorovinyl)selenium dichlorides derived from γ-phenyl- or γ-isopropenylpropargyl alcohols underwent cyclization to form benzoselenophene derivatives; this was accompanied by the formation of the corresponding dichloro-substituted allylic alcohols. In contrast, selenium tetrachloride reacts with γ-phenylpropargyl alcohol exclusively as a chlorinating agent, giving (3-chloroprop-1-yn-1-yl)benzene quantitatively. Products of regio- and stereospecific electrophilic addition of selenium tetrabromide are also described. Reaction mechanisms are proposed.
KW - alcohols
KW - alkynes
KW - electrophilic additions
KW - halides
KW - selenium
UR - http://www.scopus.com/inward/record.url?scp=79651471925&partnerID=8YFLogxK
U2 - 10.1055/s-0030-1258395
DO - 10.1055/s-0030-1258395
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AN - SCOPUS:79651471925
SN - 0039-7881
SP - 577
EP - 584
JO - Synthesis
JF - Synthesis
IS - 4
M1 - P17010SS
ER -