Highly versatile enantioselective conjugate addition of Grignard reagents to alpha,beta-unsaturated thioesters.
Herein, we report efficient catalysts for the asymmetric copper-catalyzed conjugate addition of Grignard reagents to alpha,beta-unsaturated thioesters. MeMgBr adds to aromatic alpha,beta-unsaturated thioesters with excellent enantioselectivities and moderate to good yields using Josiphos/CuBr and Tol-BINAP/CuI complexes. The use of bulky Grignard reagents leads to unprecedented enantioselectivities in the 1,4-addition to a broad range of aromatic and aliphatic alpha,beta-unsaturated thioesters using Tol-BINAP/CuI. The highest enantioselectivities reported so far for the addition of Grignard reagents to crowded beta-substituted aliphatic substrates are achieved with Tol-BINAP/CuI.
Ruiz
Beatriz Maciá
BM
Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Geurts
Koen
K
Fernández-Ibáñez
M Angeles
MA
ter Horst
Bjorn
B
Minnaard
Adriaan J
AJ
Feringa
Ben L
BL
D002384:Catalysis; D003300:Copper / Q000737:chemistry; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D004952:Esters; D007202:Indicators and Reagents; D003300:Copper