1270183-36-2Relevant academic research and scientific papers
Formation of quaternary stereogenic centers by NHC-Cu-catalyzed asymmetric conjugate addition reactions with Grignard reagents on polyconjugated cyclic enones
Tissot, Matthieu,Poggiali, Daniele,Henon, Helene,Mueller, Daniel,Guenee, Laure,Mauduit, Marc,Alexakis, Alexandre
, p. 8731 - 8747 (2012/09/25)
The copper-catalyzed conjugate addition of various Grignard reagents to polyconjugated enones (dienone and enynone derivatives) is reported. The catalyst system, composed of copper triflate and an NHC ligand, led to the unusual selective formation of the 1,4-addition products. This reaction allows for the creation of all-carbon chiral quaternary centers with enantiomeric excesses up to 99 %. The remaining unsaturation on the 1,4 adducts give access to valuable synthetic transformations. Copyright
Highly enantioselective and regioselective copper-catalyzed 1,4 addition of grignard reagents to cyclic enynones
Tissot, Matthieu,Perez Hernandez, Alexandra,Mueller, Daniel,Mauduit, Marc,Alexakis, Alexandre
, p. 1524 - 1527 (2011/05/04)
In this letter we describe an unusual result in terms of regioselectivity with respect to copper-catalyzed conjugate additions of various Grignard reagents to cyclic enynones. The use of Cu(OTf)2 and NHC ligand L1 as the catalyst combination in CH2Cl2 led to the unique formation of the 1,4 adduct. This selectivity does not follow the general trend previously observed in the literature using extended Michael acceptors. Moreover these reactions allowed for the creation of a quarternary stereogenic center with enantioselectivities up to 97% ee.
