Synthetic Applications of Homolytic Addition and Telomerisation Reactions of Bromine-Containing Addends with Unsaturated Compounds Containing Electron-Withdrawing Substituents

Mechanistic Aspects of the Kharasch Addition Reaction Catalyzed by Organonickel(II) Complexes Containing the Monoanionic Terdentate Aryldiamine Ligand System [C6H2(CH2NMe2)2-2,6-R-4]-

“…The controlled radical polymerization concept has been extended by Matyjaszewski and co-workers 7d,e for the bulk polymerization of styrene and MMA. This process uses a CuX/2,2‘-bipyridine catalyst which is similar to many of the Cu halide/amine systems that are used in Kharasch addition reactions. − A recent report by Teyssié and collaborators details the similar use of the arylnickel(II) complex ( 1 ), first synthesized in this laboratory, ,15a in a similar manner for a well-controlled radical polymerization of MMA at rather moderate temperatures 7h. This report is highly relevant to the interpretation of the new results reported herein.…”

“…The reaction has been extensively investigated both for synthetic purposes and for mechanistic information. The classical free radical chain mechanism is operative not only with initiators such as light, heat, and peroxides, but also with a variety of metal complexes . With certain substrates, it can be difficult to select for the Kharasch addition because of radical stability or activity which leads to chain propagation and, thus, the formation of 1:2 adducts, telomers and/or polymers.…”

Diaminoarylnickel(II) “Pincer” Complexes: Mechanistic Considerations in the Kharasch Addition Reaction, Controlled Polymerization, and Dendrimeric Transition Metal Catalysts

“…Virtually any olefin can serve as the source of reactive unsaturation. The list of promoters is now quite extensive and includes powdered TM's or inorganic oxides; 15 inorganic halides; 5d,6,14a,16 mono-, 12,17 di-, 18 and trinuclear metal carbonyls; 19 cyclopentadienyl and arene complexes; 18,20,21 metal phosphine compounds; 8a,9,22-25 SmI 2 ; 26 and RuCl 2 (PPh 3 ) 3 8a,27,28 or its polymer supported analogue. 29…”

Towards the development of highly active copper catalysts for atom transfer radical addition (ATRA) and polymerization (ATRP)‡

“…Alkyl halides are typically polyhalogenated alkanes (Asscher & Vofsi, 1961;Freidlina & Velichko, 1977;Julia et al, 1979a;Truce & Wolf, 1971), benzylic halides (Baban & Caronna et al, 1977;Minisci, 1975), N-haloamines (Minisci, 1975), α-halonitriles (Julia et al, 1979b;Miniotte et al, 1975), α-haloacetates (Julia et al, 1979a;Murai et al, 1964), α-haloaldehydes (Bellus, 1985;Martin et al, 1985;Steiner et al, 1982) and alkylsulfonyl halides (Amiel, 1974;Asscher & Vofsi, 1961;Block et al, 1986;Kamigata et al, 1983;Sinnreich & Asscher, 1972;Truce & Wolf, 1971). Alkenes, on the other hand, range from relatively free-radical polymerization inactive (α-olefins such as 1-hexene, 1-octene or 1-decene) to highly active (styrenes, (meth)acrylates, acrylonitrile or vinyl acetate).…”