14087-26-4Relevant articles and documents
DIACETOXYLATION OF CONJUGATED DIENES WITH THALLIUM(III) ACETATE IN ACETIC ACID
Uemura, Sakae,Miyoshi, Haruo,Tabata, Akira,Okano, Masaya
, p. 291 - 295 (1981)
The reaction of conjugated dienes such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2,5-dimethyl-2,4-hexadiene, 1,3-cyclopentadiene, and 1,3-cyclohexadiene with thallium(III) acetate in acetic acid at 10-65 deg C for 0.5-15 hr affords an isomeric mixture of the corresponding diacetoxyalkenes (1,2- and 1,4-addition products) in 10-92 percent yields.The 1,2-addition products are predominantly formed in all cases examined except the case of 1,3-cyclopentadiene.The reaction is assumed to proceed through acetoxythallation and dethallation steps, the latter step being accompanied and/or followed by an attack of acetoxyl group.An initial attack of thallium moiety is proposed to occur mainly at C-1 and C-2 carbons in the cases of linear terminal dienes and cyclic dienes, respectively.
ACYLOXYLATION OF CYCLOPENTADIENE IN THE PRESENCE OF PALLADIUM COMPLEXES
Vekki, A. V.,Trushova, N. V.
, p. 394 - 396 (2007/10/02)
Cyclopentadiene reacts with PdCl4-2 in acetic acid to form a binuclear bridged complex, which probably has an asymmetric sandwich structure with one double bond being retained in the ring.The first acetoxy group is introduced almost instantaneously.This is followed by the attack of the second AcO- group or by the decomposition of the complex to form 3-acetoxycyclopentene.With using butyric acid, 3-butyroxycyclopentene is formed with higer selectivity.In the presence of the PdCl4-2-NaNO3-KIO3 system, the reaction becomes catalytic.
Liquid-phase 1,4-Diacetoxylation of Conjugated Dienes with Tellurium(IV) Oxide and Alkali Metal Halides
Uemura, Sakae,Fukuzawa, Shin-ichi,Patil, Suresh R.,Okano, Masaya
, p. 499 - 504 (2007/10/02)
Oxidation of buta-1,3-diene, isoprene, and 2,3-dimethylbuta-1,3-diene with tellurium(IV) oxide and lithium bromide in acetic acid affords an isomeric mixture of the corresponding diacetoxyalkenes (1,2- and 1,4-addition products).The product yield and selectivity for 1,4-isomers are high when an excess of LiBr is employed (LiBr/TeO2 = 5-10).The reaction also proceeds in the presence of NaBr, KBr, LiCl, HBr, or I2 in the place of LiBr, but both the selectivity for 1,4-isomers and the product yield are lower.The reaction hardly occurs using LiF, LiI, NaCl, Br2, and NH4Br as a halogen source.The reaction proceeds catalytically with respect to TeO2 to some extent when a re-oxidant such as H2O2 or t-BuOOH is used.In the cases of 2,5-dimethylhexa-2,4-diene, cyclopenta-1,3-diene, cyclohexa-1,3-diene, and cyclo-octa-1,3-diene the results are unsatisfactory in either the product yield or the selectivity for 1,4-isomers.Halogeno- and/or acetoxy-telluriation of a diene followed by acetolysis of the produced C-X (X = halogen) and C-Te bonds are proposed as one of the possible reaction pathways.
