18993-09-4Relevant articles and documents
Reaction of Organic Halides with Chlorotris(triphenylphosphine)cobalt(I)
Momose, Den-ichi,Iguchi, Kazuo,Sugiyama, Toshikazu,Yamada, Yasuji
, p. 1840 - 1853 (2007/10/02)
Reaction of various types of organic halides with a monovalent cobalt complex, chlorotris(triphenylphosphine)cobalt(I) is described.Reaction of benzylic monohalides, dihalides and trihalides with CoCl(Ph3P)3 gave a coupling product with formation of a carbon-carbon single bond, double bond and triple bond, respectively, under mild and non-basic conditions.Dehalogenation of non-benzylic vicinal dihalides with the reagent took place cleanly to give an olefin in high yield.Reductive coupling of allylic halides using the reagent afforded regioselectively a 1,5-diene with retention of the stereochemistry of the carbon-carbon double bond of the allylic halides used.By using this reaction, (E,E,E,E)-squalene was stereospecifically synthesized from (E,E)-farnesyl bromide.Reaction of halohydrins with CoCl(Ph3P)3 gave exclusively a ketone in the presence of an amine or olefin through an alkylcobalt intermediate.A 1,2-hydrogen shift is involved in this reaction.Keywords - chlorotris(triphenylphosphine)cobalt(I); coupling reaction; benzylic halides; allylic halides; synthesis of 1,5-diene; squalene; halohydrin; ketone synthesis.
OZONOLYSIS OF ALKENES AND REACTIONS OF POLYFUNCTIONAL COMPOUNDS. XVIII. INVESTIGATION OF A NEW OZONOLYTIC SYNTHESIS OF CARBOXYLIC ACIDS
Odinokov, V. N.,Botsman, L. P.,Ishmuratov, G. Yu.,Tolstikov, G. A.
, p. 453 - 463 (2007/10/02)
By identification of the 18O isotope label in the oligomeric peroxide obtained by ozonization of a cyclic olefin in the presence of heavy oxygen and also in the product from catalytic isomerization of this peroxide ( the α,ο-dicarboxylic acids or its dimethyl ester ) it was shown that oxygen enters the ozonolysis product when the reaction is carried out in ether solvents.It is suggested that the increased content of active oxygen in the ozonolysis peroxy product is due to oxidation of the ether solvent to form α-hydroperoxide and addition of the latter to the oligomeric zwitterion, solvated by the polar solvents.It was established that the catalytic and thermal isomerization of the oligomeric peroxides and ozonides of cyclic olefins to the α,ο-dicarboxylic acids and ο-formyl carboxylic acids occurs through the oligomeric α-hydroxy peresters and α-hydroxy esters respectively.