Origins of regioselectivity in the reactions of alpha-lactams with nucleophiles. Two distinct acid-catalyzed pathways involving O- and N-protonation.
Sterically stabilized alpha-lactams react by two distinct acid-catalyzed pathways. Protonation on oxygen results in nucleophilic attack at the acyl carbon and gives C-2 products. Protonation on nitrogen leads to nucleophilic attack at the C-3 carbon and yields C-3 products. The mechanism thus developed is very useful for understanding the changes in rates and product distributions in the reactions of sterically stabilized alpha-lactams with nucleophiles. It can also be extrapolated to other alpha-lactams so that a more coherent picture of alpha-lactam reactivity can be developed.
Department of Chemistry and Biochemistry, North Horseshoe Drive, New Mexico State University, Las Cruces, New Mexico 88003-8001, USA. rhoffman@nmsu.edu
Robert V
RV
Hoffman
Zhiqiang
Z
Zhao
Abran
A
Costales
David
D
Clarke