15174-76-2Relevant academic research and scientific papers
TiCl4-n-Bu3N-mediated cascade annulation of ketones with α-ketoesters: A facile synthesis of highly substituted fused γ-alkylidene-butenolides
Palange, Megha N.,Gonnade, Rajesh G.,Kontham, Ravindar
, p. 5749 - 5759 (2019/06/18)
A facile protocol for the synthesis of highly substituted fused γ-alkylidene butenolides using direct annulation of ketones with α-ketoesters, which proceeds through TiCl4-n-Bu3N mediated aldol addition followed by an intramolecular
Solid-supported copper catalysts for atom-transfer radical cyclizations: Assessment of support type and ligand structure on catalyst performance in the synthesis of nitrogen heterocycles
Clark, Andrew J.,Geden, Joanna V.,Thom, Stephen
, p. 1471 - 1479 (2007/10/03)
A range of solid supported pyridinemethanimine 9-11 and polyamine 12-15 ligands have been prepared on silica, polystyrene, and JandaJel supports. The CuCl and CuBr complexes of these supported ligands have been used to assess both the effect of the ligand type and the nature of the support upon a representative range of copper-mediated atom transfer 5-exo-trig 6, 24-25, 5-exo-dig 26, 4-exo-trig 28, and 5-endo-trig 27, 38 radical cyclizations to give nitrogen heterocycles. In addition, the effect of the nature of the support on the stereochemical outcome of the 5-exo cyclization of 25 has been probed. Generally, it was found that the type of support (e.g., polystyrene, silica, or JandaJel) had very little effect upon the efficiency and selectivity of the processes but that the nature of the ligand type immobilized was the important factor. Thus, the 5-exo cyclization of 6 and 24-26 proceeded more rapidly with the PMI ligands 9-11, whereas 4-exo cyclizations 28 and 5-endo radical polar crossover reactions 27 and 38 proceeded more efficiently with the JJ-TEDETA ligand 15. The efficiency of the supported ligands was also compared to their solution counterparts 4 and 5. The reusability of P-PMDETA ligand system 13 was assessed in the cyclization of 6.
Influence of copper(II) acetate on Ni/AcOH-promoted 5-endo and 5-exo radical cyclisations of trichloroacetamides
Cassayre, Jér?me,Dauge, Delphine,Zard, Samir Z.
, p. 471 - 474 (2007/10/03)
Incorporation of Cu(OAc)2 as oxidant in Ni/AcOH-promoted 5-endo radical cyclisations of N-alkenyl-trichloroacetamides allows an interesting control of the oxidation level of the products, as illustrated by the conversion of 3 into either 4 or 5. In addition, allylic trichloroacetamides 13a-f under the same conditions underwent a 5-exo radical cyclisation-oxidation sequence leading to unsaturated hydroindolones, which represent valuable synthetic intermediates.
Aromatization of Aliphatic Compounds. VII (1). Benzofuranones, Indoles and Oxindoles
Giannangeli, M.,Baiocchi, L.
, p. 891 - 895 (2007/10/02)
2(4H)-5,6-Dihydrobenzofuranones 3 gave, when treated with pyridine hydrochloride at 200 deg, the corresponding arylacetic acids 1 in good yields, whereas the aza analogues, the tetrahydrooxindoles 6 gave indoles in poor yields.The oxidation products of 3 (11 and 13) and of 6 (12, 14 and 15) gave, with the same reagent, benzofuranones and oxindoles, respectively, both in good yields.
