928-60-9Relevant academic research and scientific papers
α,ω-Dialkyl-Substituted Polyenes by Palladium-Catalyzed Coupling Reactions of Vinyltin Compounds with Vinyl Halides
Kiehl, Alfried,Eberhardt, Anke,Muellen, Klaus
, p. 223 - 230 (2007/10/02)
α,ω-Dialkyl-substituted linear polyenes are synthesized in good yields by the palldium-catalyzed coupling reaction of trialkyltin- and iodo-substituted olefinic precursors.Central building blocks are the distannylated butadiene 8 and vinyl iodide 3.Our synthetic strategy was successfully applied to the preparation of the tert-butyl polyenes 13, 14, and 15 as well as polyenes 25 and 26 with longer α,ω-dialkyl chains. - Key Words: Polyenes, linear/ Vinyl tin compounds/ Vinyl halides/ Palladium catalysis
CHLORIERENDE METHYLIERUNG VON ALDEHYD- UND KETOGRUPPEN MIT NIOB-REAGENZIEN SOWIE AUFKLAERUNG DES MECHANISMUS
Kauffmann, Thomas,Abel, Thomas,Neiteler, Gabriele,Schreer, Martin
, p. 503 - 506 (2007/10/02)
The reagents MeNbCl4 and Me2NbCl3, applied as isolated pure compounds, react with ketones in preparatively useful yields according to RR'CO -> RR'C(Cl)CH3.Whereas benzaldehyde reacts with MeNbCl4 analogously, the aliphatic aldehyde heptanal forms beside the expected product two cinechlorination products, indicating a mechanism via radicals.MeNbCl4 is highly aldehyde-vs.-ketone selective.Conversely, high ketone-vs.-aldehyde selectivity is achievable by application of MeNbCl4*PPh3 or NbCl5*PPh3 + 1.5 Me2Zn.
REGIOSPECIFIC AND STEREOSPECIFIC SUBSTITUTION OF HYDROXYL IN ALIPHATIC ALCOHOLS BY HALOGEN
Matveeva, E. D.,Kurts, A. L.,Yalovskaya, A. I.,Nikishova, N. G.,Bundel', Yu. G.
, p. 642 - 646 (2007/10/02)
A new system containing triphenylphosphine and trichloro- and tribromoacetic ester makes it possible to substitute the hydroxyl group in alcohols by halogen.Regiospecific and stereospecific substitution of the hydroxyl by the halogen takes place as a result of the reaction of primary and secondary aliphatic alcohols and of 2-alkenols, susceptible to isomerization processes, with this system.
