1,6-Asymmetric induction during the conjugate addition of arylcopper reagents to a chiral sulfinyl-substituted pyrrolyl alpha,beta-unsaturated amide.
The asymmetric conjugate addition of arylcopper reagents derived from aryl Grignard reagents and copper(I) iodide to a chiral 1-[2-(p-tolylsulfinyl)]pyrrolyl cinnamide proceeded smoothly to give (3R)-adducts with high diastereoselectivities (> or =92% de) in high yields. Conjugate additions either of the cinnamide with the alkyl Grignard reagent-copper(l) iodide combination or of the crotonamide derivative with aryl Grignard reagent-copper(l) iodide gave moderate to good diastereoselectivities. With these sulfinyl pyrrolyl alpha,beta-unsaturated amides, the chiral auxiliary was efficiently recovered without any loss of optical purity after asymmetric conjugate addition.
Arai
Y
Y
Gifu Pharmaceutical University, Japan. araiy@gifu-pu.ac.jp
Ueda
K
K
Xie
J
J
Masaki
Y
Y
D002851:Chromatography, High Pressure Liquid; D003300:Copper / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009942:Organometallic Compounds / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013450:Sulfones / Q000737:chemistry*
D007202:Indicators and Reagents; D009942:Organometallic Compounds; D011758:Pyrroles; D013450:Sulfones; D003300:Copper