4439-87-6Relevant articles and documents
Bimetallic Phase Transfer Catalysis
Alper, Howard,Petrignani, Jean-Francois
, p. 1154 - 1155 (1983)
γ-Keto acids are obtained by the phase transfer catalysed reaction of alkynes with carbon monoxide and methyl iodide in the presence of catalytic amounts of cobalt and ruthenium carbonyl complexes.
Formation of γ-oxoacids and 1 H-pyrrol-2(5 H)-ones from α,β-unsaturated ketones and ethyl nitroacetate
Aginagalde, Maialen,Bello, Tamara,Masdeu, Carme,Vara, Yosu,Arrieta, Ana,Cossio, Fernando P.
experimental part, p. 7435 - 7438 (2010/12/25)
Michael addition of ethyl nitroacetate on α,β-unsaturated ketones followed by Nef oxidation under hydrolytic conditions yields γ-oxoacids instead of the corresponding α,δ-dioxoesters. A concerted decarboxylation step is proposed on the basis of computational results. Finally, conversion of the γ-ketoacids thus prepared into 1H-pyrrol-2(5H)-ones by reaction with primary amines under Paal-Knorr conditions is also reported.
Predominant 1,2-insertion of styrene in the Pd-catalyzed alternating copolymerization with carbon monoxide
Nozaki,Komaki,Kawashima,Hiyama,Matsubara
, p. 534 - 544 (2007/10/03)
The regioselectivity of styrene insertion to an acyl-Pd bond was studied by NMR in (i) a stoichiomeric reaction and (ii) a copolymerization with CO. In the stoichiometric reaction of styrene with [(CH3CO)Pd-(CH3CN){(R,S)-BINAPHOS}] ·[B{3,5-(CF3)2C6 H3}4], both 1,2-and 2,1-products were given. To mimic the real polymerization conditions, a polyketone-substituted complex [{CH3(CH2CHCH3CO)n}Pd{(R,S)-BINAP HOS}]·[B(3,5-(CF3)2C6 H3)4] (n ≈ 14) was prepared. When this polymer-attached Pd species was treated with styrene, the 1,2-insertion product was the only detectable species. Thus, exclusive 1,2-insertion is demonstrated to be responsible for the styrene-CO copolymerization, in sharp contrast to the predominant 2,1-insertion with conventional nitrogen ligands. Chain-end analysis revealed that β-hydride elimination took place from the 2,1-complex but not from the 1,2-complex. Thus, once 2,1-insertion occurs, rapid β-hydride elimination proceeds to terminate the polymerization, as is common to the other phosphorus-ligand systems. The resulting Pd-H species re-initiates the copolymerization, as was proven by MALDI-TOF mass analysis of the product copolymers.
