Diazo Reagents in Copper(I)-Catalyzed Olefination of Aldehydes
作者:Hélène Lebel、Michaël Davi
DOI:10.1002/adsc.200800381
日期:2008.10.6
The olefination of aldehydes to synthesize unsaturated ketones, esters, amides and phosphonates using diazo reagents and triphenylphosphine in the presence of copper(I) iodide as catalyst, is described. Good to excellent E:Z selectivities as well as yields were obtained for a large variety of aliphatic, aromatic and heteroaromatic aldehydes. The reaction showed also an excellent functional group compatibility
Electroreductive coupling of aromatic ketones, aldehydes, and aldimines with α,β-unsaturated esters: Synthesis of 5-aryl substituted γ-butyrolactones and lactams
作者:Naoki Kise、Yusuke Hamada、Toshihiko Sakurai
DOI:10.1016/j.tet.2017.01.013
日期:2017.2
The electroreductive intermolecular coupling of aromatic ketones and aldehydes with α,β-unsaturated esters in the presence of TMSCl gave the adducts as γ-trimethylsiloxy esters. The detrimethylsilylation of the adducts with TBAF afforded 5-aryl substituted γ-butyrolactones. The electroreductive coupling of N-(4-methoxyphenyl)-1-arylmethaneimines with methyl acrylate in the presence of TMSCl gave the
Enantioselective Synthesis of 2,6-<i>cis</i>-Disubstituted Tetrahydropyrans via a Tandem Catalytic Asymmetric Hydrogenation/Oxa-Michael Cyclization: An Efficient Approach to (−)-Centrolobine
A highly efficient one-pot process via a tandemreaction of catalytic asymmetric hydrogenation and oxa-Michael cyclization for the synthesis of 2,6-cis-disubstituted tetrahydropyrans has been developed (ee up to 99.9%, cis/trans-selectivity up to 99:1). This method provides a concise route to (−)-centrolobine (68.8% yield, three steps).