17920-90-0Relevant articles and documents
Me5Cu3Li2: A Reagent for Conjugate Methylation of α,β-Unsaturated Aldehydes
Clive, Derrick L.J.,Farina, Vittorio,Beaulieu, Pierre L.
, p. 2572 - 2582 (2007/10/02)
Me5Cu3Li2, in ether or ether-pentane mixtures, converts α,β-unsaturated aldehydes efficiently into β-methyl aldehydes.In many cases of synthetic interest the amount of 1,2-methylation is negligible, and the reagent is far superior to Me2CuLi for conjugate methylation of enals.The performance of Me5Cu3Li2 is poor in sterically demanding situations, however.Several cuprate species were evaluated but none works as well as Me5Cu3Li2.For example, citral undergoes conjugate methylation with Me5Cu3Li2 in 80percent yield, and the product contains less than 0.5percent of 1,2-adduct.With Me2CuLi the product contains 10percent of 1,2-adduct.
ACTION DES DIALKYLCUPRATES DE LITHIUM SUR LES ALDEHYDES α,β-ETHYLENIQUES
Chuit, C.,Foulon, J. P.,Normant, J. F.
, p. 2305 - 2310 (2007/10/02)
Nearly exclusive 1-4 addition products are obtained by action of lithium dialkylcuprates with α,β-ethylenic aldehydes.Non polar solvents and low temperatures favor this reaction.Only α,β-ethylenic aldehydes having a trisubstituted double bond give a relatively important proportion of 1-2 addition product.
