2345-32-6Relevant academic research and scientific papers
Catalysts based on vanadium, their preparation and use in the (co)polymerization of alpha-olefins.
-
, (2008/06/13)
Vanadium complex having general formula (I)(RCOO)mVXpLm wherein R is a monofunctional hydrocarbon radical having from 1 to 20 carbon atoms and from 1 to 6 halogen atoms, selected from chlorine and bromine, preferably chlorine; X is chlorine or bromine, preferably chlorine; L is an electron donor; p+n= 3, 4 or 5, preferably = 3; n is greater than or equal to 1; m is between 0 and 3. The preparation of the above complex is also described together with its use in the (co)polymerization of α-olefins.
Catalyst Effects on Reactions of α,β-Unsaturated Ketones and Esters with Haloforms under Phase-Transfer Catalysis
Dehmlow, Eckehard V.,Wilkenloh, Juergen
, p. 582 - 588 (2007/10/02)
Reactions of acceptor-substituted alkenes with haloform/sodium hydroxide and PT-catalyst result in dihalocarbene additions competitive to Michael additions, with or without consecutive cyclization, and further reactions.Product compositions are strongly dependent on the nature of the phase-transfer catalyst: Sterically unhindered quarternary ammonium ions and benzo-crown ethers favour processes via carbenes, large delocalized (soft) cations foster primary Michael additions.Thus, tert-butyl cis-crotonate is dichlorocyclopropanated stereospecifically with NMe4Cl.The respective stereospecific CBr2 conversion is successful only with PhHgCBr3 .
Synthesis of Polyhalogenated Butyryl Chlorides, Precursors of Pyrethroid Haloketenes
Martin, Pierre,Steiner, Eginhard,Bellus, Daniel
, p. 1947 - 1957 (2007/10/02)
The copper(I)-catalyzed free radical addition of halomethanes to acrylates and the addition of halogenated acetic acid derivatives to fluoro- or chloro-substituted ethylenes affords polyhalogenated butyric acid derivatives.Chlorides of these acids serve as precursors for haloketenes used in efficient syntheses of pyrethroids.
