Solvent-Free Knoevenagel Condensation over Cobalt Hydroxyapatite
摘要:
The Knoevenagel condensation between various aldehydes (benzaldehyde, 1-naphthaldehyde, p-bromobenzaldehyde and p-methoxybenzaldehyde) and esters (ethylcyanoacetate, ethylacetoacetate and diethylmalonoester) was carried out under solvent free condition in the presence of cobalt hydroxyapatite (CoHAp), as a catalyst. Good to excellent yields (35-96%) were obtained. The catalyst is found to be superior over fluorapatite and several other heterogeneous catalysts. The catalyst can be recycled at least 3 times.
Nickel-catalyzed [3 + 2] Cycloaddition of α,β-Unsaturated Ketones with Vinyl Oxiranes
作者:Saori Sako、Takuya Kurahashi、Seijiro Matsubara
DOI:10.1246/cl.2011.808
日期:2011.8.5
A nickel-catalyzed cycloaddition of α,β-unsaturated ketones with vinyl oxiranes to afford polysubstituted tetrahydrofurans has been developed. The key intermediate is a five-membered nickelacycle, ...
Solvent-free Knoevenagel condensation over iridium and platinum hydroxyapatites
作者:M. K. Pillai、S. Singh、S. B. Jonnalagadda
DOI:10.1134/s0023158411030153
日期:2011.7
The Knoevenagel condensation between various aldehydes (benzaldehyde, p-methoxybenzaldehyde and 1-naphthaldehyde) and esters (ethylcyanoacetate, ethylacetoacetate and diethylmalonoester) was carried out under solvent-free condition in the presence of iridium or platinum hydroxyapatites as a catalyst.
Reactions of Organometallic Compounds with Conjugated Enol Ethers: Synthesis of β-Arylacrylates, Diarylmethylmalonates and Analogous Compounds
作者:D. P. Nabar、S. V. Sunthankar
DOI:10.1246/bcsj.42.2991
日期:1969.10
Methylenecyclopropanes in [4 + 1] Cycloaddition with Enones
A nickel-catalyzed [4 + 1] cycloaddition of enones with methylenecyclopropanes leading to dihydrofurans was developed. The reaction outcome is attributed to the transformation of methlenecyclopropane, which is incorporated Into a five-membered ring as a one-carbon fragment.