TY - JOUR
T1 - Influence of the Organocatalyst in the Aldol/Mannich-Type Product Selectivities in C−C Bond Forming Reactions
AU - Dominguez de Maria, Pablo
AU - Bracco, Paula
AU - Castelhano, Luiz Fernando
AU - Bargeman, Gerrald
PY - 2011
Y1 - 2011
N2 - Several organocatalysts were tested in the cross condensation of isobutyraldehyde and acetone. Formation of aldol-type and Mannich-type (“aldol condensation”) products was assessed, and Aldol/Mannich proportion studied under several reaction conditions and at different conversions. Organocatalysts able to form Seebach’s oxazolidinones, proline and prolinol, led to high Aldol/Mannich relationships (60−10, depending on organocatalyst, reaction conditions, and conversions), whereas organocatalysts unable to form such oxazolidinones (pyrrolidine, O-methylprolinol and proline tbutyl ester) yielded much lower Aldol/Mannich relationships in all conditions and conversions studied (<2.8). These results suggest that Seebach’s oxazolidinones might act as “controllers” of the reaction, thus partly avoiding the formation of the Mannich-type adducts, by removing activated forms of aldehyde from the catalytic cycle.
AB - Several organocatalysts were tested in the cross condensation of isobutyraldehyde and acetone. Formation of aldol-type and Mannich-type (“aldol condensation”) products was assessed, and Aldol/Mannich proportion studied under several reaction conditions and at different conversions. Organocatalysts able to form Seebach’s oxazolidinones, proline and prolinol, led to high Aldol/Mannich relationships (60−10, depending on organocatalyst, reaction conditions, and conversions), whereas organocatalysts unable to form such oxazolidinones (pyrrolidine, O-methylprolinol and proline tbutyl ester) yielded much lower Aldol/Mannich relationships in all conditions and conversions studied (<2.8). These results suggest that Seebach’s oxazolidinones might act as “controllers” of the reaction, thus partly avoiding the formation of the Mannich-type adducts, by removing activated forms of aldehyde from the catalytic cycle.
U2 - 10.1021/cs100088m
DO - 10.1021/cs100088m
M3 - Article
VL - 1
SP - 70
EP - 75
JO - ACS catalysis
JF - ACS catalysis
SN - 2155-5435
IS - 2
ER -