Asymmetric syn-selective Henry reaction catalyzed by the sulfonyldiamine-CuCl-pyridine system.
A catalytic asymmetric Henry reaction has been developed with use of a sulfonyldiamine-CuCl complex as a catalyst. A series of new binaphthyl-containing sulfonyldiamine ligands (2a-h) were readily synthesized in two steps starting from commercially available chiral 1,2-diamines. The (R,R)-diamine-(R)-binaphthyl ligand (2d)-CuCl complex smoothly catalyzed the enantioselective Henry reaction with the assistance of pyridine to give the corresponding adduct with high enantiomeric excess (up to 93%). Moreover, the 2d-CuCl-pyridine system promotes the diastereoselective Henry reaction in syn-selective manner to give the adduct in up to 99% yield with 92:8 syn/ anti selectivity. The enantiomeric excess of the syn-adduct was 84% ee.
Arai
Takayoshi
T
Department of Chemistry, Graduate School of Science, Chiba University, Inage, Chiba 263-8522, Japan. tarai@faculty.chiba-u.jp
Takashita
Ryuta
R
Endo
Yoko
Y
Watanabe
Masahiko
M
Yanagisawa
Akira
A
D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*
D011725:Pyridines; D003300:Copper; C028419:cuprous chloride