Rhodium-Catalysed Alkoxycarbonylative Cyclisation Reactions of 1,6-Enynes
作者:Fırat Ziyanak、Melih Kuş、Levent Artok
DOI:10.1002/adsc.201000772
日期:2011.4.18
The rhodium‐catalysedcarbonylation of 1,6‐enynes possessing an electron‐deficient alkenyl moiety in an alcohol reagent in the presence of a rhodiumcomplex proceeded stereo‐ and chemoselectively to afford exocyclic α,β‐enoates.
From stoichiometry to catalysis: electroreductive coupling of alkynes and carbon dioxide with nickel-bipyridine complexes. Magnesium ions as the key for catalysis
作者:Sylvie Derien、Elisabet Dunach、Jacques Perichon
DOI:10.1021/ja00022a037
日期:1991.10
The incorporation of carbon dioxide into nonactivated alkynes catalyzed by electrogenerated nickel-bipyridine complexes affords alpha,beta-unsaturated acids in moderate to good yields. The electrocarboxylation reaction was undertaken on a preparative scale in the presence of a sacrificial magnesium anode: the formation of acids from alkynes is stoichiometric with respect to the nickel complex if performed in a two-compartment cell but can be made catalytic in a single-compartment cell. An intermediate nickelacycle was isolated from the reaction with 4-octyne. The cleavage of this metallacycle by magnesium ions is the key step to explain catalysis.
Iodine-mediated Z-selective oxidation of ketones to α,β-unsaturated esters: synthesis and mechanistic studies
作者:Michael J. Zacuto、Dongwei Cai
DOI:10.1016/j.tetlet.2005.09.176
日期:2005.11
Z-selective oxidation of simple acyclic ketones to Z-2,3-trisubstituted α,β-unsaturatedesters is described. Enolates generated under the reaction conditions undergo double iodination followed by a Favorskii-related rearrangement to the unsaturated ester. This reaction represents the first stereoselective one-step transformation of ketones to α,β-unsaturatedesters. Mechanistic studies suggest that an