Optimization of the catalytic asymmetric addition of nitroalkanes to cyclic enones with trans-4,5-methano-L-proline.
[reaction: see text] The conjugate addition of symmetrical 2-nitroalkanes to 2-cycloalkenones catalyzed by trans-4,5-methano-l-proline proceeds with >99% ee and excellent chemical yields. 1-Nitroalkanes afford diastereomeric syn/anti products that can be separated with good individual enantioselectivities. Proline hydroxamic acid and its trans-4,5-methano -l-proline hydroxamic acid are also effective organocatalysts in the addition of 2-nitropropane to 2-cyclohexenone (75% and 81% ee, respectively).
Hanessian
Stephen
S
Department of Chemistry, Université de Montréal, P.O. Box 6128, Station Centre-ville, Montréal, QC H3C 3J7, Canada. stephen.hanessian@umontreal.ca
Shao
Zhihui
Z
Warrier
Jayakumar S
JS
D000473:Alkanes / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D006877:Hydroxamic Acids / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009574:Nitro Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives* / Q000737:chemistry*; D013237:Stereoisomerism
C520392:4,5-methanoproline; D000473:Alkanes; D006877:Hydroxamic Acids; D009574:Nitro Compounds; D011392:Proline