Cyclisation of acetylenecarboxylic acid. Synthesis of γ-methylenebutyrolactones
作者:Makoto Yamamoto
DOI:10.1039/p19810000582
日期:——
Various γ-exo-methylenebutyrolactones have been synthesized in excellent yield by the cyclisation of acetylenecarboxylicacids in the presence of a catalytic amount of mercury(II) oxide. Cyclisation of terminal acetylene compounds[e.g.(1a)–(1e)]proceeded regioselectively to give γ-exo-methylenebutyrolactones as the sole product. Disubstituted acetylenes [(1f)–(1i)] also gave the (Z)-configurational
Gold nanoparticles stabilized by PEG-tagged imidazolium salts as recyclable catalysts for the synthesis of propargylamines and the cycloisomerization of γ-alkynoic acids
stabilizers for the preparation of water-soluble gold nanoparticles by reduction of tetrachloroauric acid with sodiumborohydride. The nanomaterials have been characterized. The X-Ray Photoelectron Spectroscopy (XPS) indicated the presence of Au(I) and Au(0) species, the oxidized form being more abundant in the nanomaterial derivedfrom the tris-imidazolium bromide. The catalytic activity of these gold
Anticancer platinum complexes as non-innocent compounds for catalysis in aqueous media
作者:José Alemán、Virginia del Solar、Carmen Navarro-Ranninger
DOI:10.1039/b917758b
日期:——
An efficient cyclization of alkyne-acids to enol-lactones catalyzed by anticancer platinum(II) and platinum(IV) compounds is described. These compounds are not only DNA-binding complexes; they can also catalyze reactions in solvents such as acetone, methanol, water or blood plasma.
2-bis(3-arylprop-2-yn1-yl)malonic acid has been proposed as an efficient approach to substituted 3,8-dibenzyl-2,7-dioxaspiro[4.4]nonane-1,6-diones. The reaction proceeds smoothly in mild reaction conditions to give the desired products in quantitative yields in the presence of variously substituted starting materials. In addition, the synthesis of γ-arylidene spirobislactone bearing different substituents