5331-13-5Relevant articles and documents
Variations in the blaise reaction: Conceptually new synthesis of 3-amino enones and 1,3-diketones
Rao, H. Surya Prakash,Muthanna, Nandurka
supporting information, p. 1525 - 1532 (2015/03/04)
Organic compounds with 3-amino enone or 1,3-diketone functional groups are extremely important, as they can be converted into a plethora of heterocyclic or carbocyclic compounds, or can be used as ligands in metal complexes. We have achieved a new, easy, straightforward and convenient synthesis of 3-amino enones and 1,3-diketones starting from aryl/heteroaryl/alkyl nitriles and 1-aryl/alkyl 2-bromoethanones. The reaction is a variation of the classical Blaise reaction, and it works with zinc and trimethylsilyl chloride as an activator. By running the hydrolysis of the reaction intermediate with HCl (3 N aq.) at 0-30 °C or at 100 °C, it is possible to form either 3-amino enones or 1,3-diketones, respectively. The newly developed method was used for the synthesis of avobenzone, an ingredient of sun-screen lotions. Furthermore, an easy synthesis of (Z)-3-amino-1-[4-(tertbutyl) phenyl]-3-(4-methoxyphenyl)prop-2-en-1-one, with UV/Vis absorption characteristics similar to those of avobenzone, was also achieved.
Formation of functionalized 2H-azirines through phio-mediated trifluoroethoxylation and azirination of enamines
Sun, Xiaoqian,Lyu, Youran,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
supporting information, p. 6222 - 6225 (2014/01/17)
A variety of enaminones and enamine carboxylic esters were converted to trifluoroethoxylated 2H-azirines through reactions with PhIO in trifluoroethanol (TFE). The cascade reaction is postulated to proceed via a PhIO-mediated oxidative trifluoroethoxylation and a subsequent azirination of the α-trifluoroethoxylated enamine intermediates.
Iodomethane oxidative addition and CO migratory insertion in monocarbonylphosphine complexes of the type [Rh((C6H5)COCHCO((CH2)n CH3))(CO)(PPh3)]: Steric and electronic effects
Stuurman, Nomampondomise F.,Conradie, Jeanet
experimental part, p. 259 - 268 (2009/04/13)
The chemical kinetics, studied by UV/Vis, IR and NMR, of the oxidative addition of iodomethane to [Rh((C6H5)COCHCOR)(CO)(PPh3)], with R = (CH2)nCH3, n = 1-3, consists of three consecutive reaction steps that involves isomers of two distinctly different classes of RhIII-alkyl and two distinctly different classes of RhIII-acyl species. Kinetic studies on the first oxidative addition step of [Rh((C6H5)COCHCOR)(CO)(PPh3)] + CH3I to form [Rh((C6H5)COCHCOR)(CH3)(CO)(PPh 3)(I)] revealed a second order oxidative addition rate constant approximately 500-600 times faster than that observed for the Monsanto catalyst [Rh(CO)2I2]-. The reaction rate of the first oxidative addition step in chloroform was not influenced by the increasing alkyl chain length of the R group on the β-diketonato ligand: k1 = 0.0333 ([Rh((C6H5)COCHCO(CH2CH3))(C O)(PPh3)]), 0.0437 ([Rh((C6H5)COCHCO(CH2CH2CH 3))(CO)(PPh3)]) and 0.0354 dm3 mol-1 s-1 ([Rh((C6H5)COCHCO(CH2CH2 CH2CH3))(CO)(PPh3)]). The pKa′ and keto-enol equilibrium constant, Kc, of the β-diketones (C6H5)COCH2COR, along with apparent group electronegativities, χR of the R group of the β-diketones (C6H5)COCH2COR, give a measurement of the electron donating character of the coordinating β-diketonato ligand: (R, pKa′, Kc, χR) = (CH3, 8.70, 12.1, 2.34), (CH2CH3, 9.33, 8.2, 2.31), (CH2CH2CH3, 9.23, 11.5, 2.41) and (CH2CH2CH2CH3, 9.33, 11.6, 2.22).
