Page 33 - Academic Press Encyclopedia of Physical Science and Technology 3rd Organic Chemistry

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Encyclopedia of Physical Science and Technology EN001F-4 May 7, 2001 16:19

Acetylene 85

The reaction of the selenium triad (Se–KOH–DMSO) Divinylsulfide(DVS)isoneofthemostimportantprod-
with acetylene yields a significant amount of 2-vinyloxy- ucts discussed, since it can be formed in 98% yield from
1,3-butadiene, besides the expected divinyl selenide: hydrogen sulfide and acetylene:
KOH−DMSO
H 2 S + C 2 H 2 −−−−−−→ (H 2 C CH) S
C 2 H 2 + Se 8 + KOH + H 2 O −→ 2
◦
80–100 C DVS (98%)
(CH 2 CH) 2 Se + CH 2 C CH CH 2 The reaction involving the addition of sulfide ion to
acetylene may involve a one-step concerted mechanism,
O CH CH 2
26% 20% since all attempts to isolate monovinyl sulfide have failed.
Either sodium sulfide or sulfur (cyclic S 8 ) can be used as
Thisby-productresultsfromthecompetitivehydration– thestartingmaterial,withtheyieldsbeingsomewhatlower
trimerization of acetylene vs vinylation. Also, the lower (80%) than with H 2 S. However, the use of elementary
yield of divinyl selenide is believed to be due to the rapid sulfur has an economic advantage.
oxidation of selenide ions by DMSO. DVS has been studied extensively as a starting ma-
The tellurium triad gives a yield (54%) intermediate terial for other products via additions across its double
between the sulfur- and selenium-based reactions: bonds, cycloadditions, free-radical reactions, and elec-
trophilic additions. A potentially important derivative is
HMPA divinyl sulfoxide (DVSO) made by the oxidation of DVS
C 2 H 2 + Te + KOH + H 2 O −−−−→ (H 2 C CH) 2 Te
110−120 C with hydrogen peroxide:
◦
54% H 2 O 2 /H 2 O
DVS −−−−→ (CH 2 CH) 2 S → O
50 C
◦
The same reaction carried out in DMSO gives only a While DVS is inert to nucleophiles, DVSO is quite ac-
30% yield. The most important commercial aspect of these tiveinMichael-typeadditions,leadingtonumerousmono-
reactions is the process for divinyl sulfide, since sulfur is and di-adducts based on reactions with amines, alcohols,
an inexpensive abundant raw material. thiols, and active C H compounds.

NHR 2 EtOH
CH 2 CH S CH 2 CH 2 NR 2
°
30–50 C O
S O
(CH 2 CH) 2
2NHR 2
(R 2 N CH 2 CH 2 ) 2 S
O

D. New Reactions and Chemicals DVS readily polymerizes with free-radical catalysts
and, as a cross-linking agent, yields macroreticular
Based on Sulfur and Acetylene
copolymers, which have excellent ion-exchange proper-
Trofimov’s research in acetylene–sulfur chemistry in- ties. DVSO has potential as a monomer in various copoly-
cludes the activation of anions and triple bonds with su- mer systems and as a synthon for making new monovinyl
perbase systems, the reaction of sulfur nucleophiles with derivatives.
acetylene in superbase media, the reaction of substituted
acetylenes with chalcogen nucleophiles (sulfur, selenium,
tellurium) in superbasic media, and prospective applica-
E. Vinylox (2-Vinyloxyethoxymethyl Oxirane)
tions. He predicts that in the future both acetylene and sul-
furwillbesourcesofinexpensiverawmaterialsformaking Vinylox is a monomer with interesting commercial po-
important acetylene–sulfur chemicals. Aprotic solvents tential. It is produced by partial vinylation of ethylene
such as DMSO and HMPA are required for the high yields glycol followed by condensation of the resulting 2-vinyl-
obtained. oxyethanol with epichlorohydrin.