Intermolecular Nonreductive Alkylation of Enamides via Radical−Polar Crossover
摘要:
A carbon-carbon bond construction method is disclosed which involves radical addition of alpha-haloesters or iodoacetonitrile to enamides. Despite the presence of tri-n-butylstannane, nonreductive addition was predominant; H-atom transfer from tin hydride was not observed. Rapid iodine atom transfer to (or electron transfer from) the radical adduct, resulting in an iminium ion intermediate and radical chain propagation, is consistent with the observed reactivity.
The three‐component free‐radical carbo‐alkenylation of electron‐richolefins has been studied, varying the substitution pattern in the alkene, in the radical precursor and in the final acceptor. New vinylsulfones were also prepared and their reactivity investigated. The scope and limitations of the process was established, and the reaction mechanism clarified using selected dienes as radical clocks
The addition of xanthates and vinyldisulfones across the double bond of enamides and ene-carbamates provides access to the corresponding three.. component adducts in good to excellent yields with a high level of diastereocontrol in cyclic systems. This strategy illustrates a complementary reactivity for these versatile olefins and extends their scope of application.
VERWENDUNG VON POLYMERDISPERSIONEN IN BESCHICHTUNGSMASSEN
申请人:BASF SE
公开号:EP2066756B1
公开(公告)日:2010-07-14
USE OF POLYMER DISPERSIONS IN COATING MATERIALS
申请人:Roschmann Konrad
公开号:US20100028546A1
公开(公告)日:2010-02-04
The present invention relates to the use in coating compositions of polymer dispersions comprising polymer particles having differently crosslinked regions intraparticulately.
[DE] VERWENDUNG VON POLYMERDISPERSIONEN IN BESCHICHTUNGSMASSEN<br/>[EN] USE OF POLYMER DISPERSIONS IN COATING MATERIALS<br/>[FR] UTILISATION DE DISPERSIONS DE POLYMÈRES DANS DES MATÉRIAUX DE REVÊTEMENT
申请人:BASF AG
公开号:WO2008034816A1
公开(公告)日:2008-03-27
[EN] The present invention relates to the use of polymer dispersions which comprise polymer particles which have intraparticulately differently crosslinked regions in coating materials. [FR] La présente invention concerne l'utilisation de dispersions de polymères, qui présentent des particules de polymères, qui présentent des zones intra-particulaires différemment réticulées, dans des matériaux de revêtement. [DE] Die vorliegende Erfindung betrifft die Verwendung von Polymerdispersionen, die Polymerpartikel aufweisen, die intrapartikulär unterschiedlich vernetze Bereiche aufweisen, in Beschichtungsmassen.