P(RNCH(2)CH(2))(3)N: efficient 1,4-addition catalysts.
The 1,4-addition of primary alcohols, higher nitroalkanes, and a Schiff's base of an alpha-amino ester to alpha,beta-unsaturated substrates produces the corresponding products in moderate to excellent yields when carried out at -63 to 70 degrees C in the presence of catalytic amounts of the nonionic strong bases P(RNCH(2)CH(2))(3)N (R = Me, i-Pr, i-Bu) in isobutyronitrile. Diastereoselectivity for the anti form of the product is high in the case of the Schiff's base in the absence of lithium ion. These catalysts are easily removed from the product by either column filtration through silica gel or via aqueous workup.
Kisanga
Philip B
PB
Department of Chemistry, Gilman Hall, Iowa State University, Ames, IA 50011, USA.
Ilankumaran
Palanichamy
P
Fetterly
Brandon M
BM
Verkade
John G
JG