Enantioselective Conjugate Addition of Both Aromatic Ketones and Acetone to Nitroolefins Catalyzed by Chiral Primary Amines Bearing Multiple Hydrogen-Bonding Donors
of chiral primary amine catalysts bearing multiple hydrogen-bonding donors have been designed and synthesized. The newly developed bifunctional organocatalysts efficiently catalyzed not only enantioselectiveconjugateaddition of aromatic ketones to nitroolefins in good yields (up to 87%) with excellent enantioselectivities (97→99% ee) but also enantioselectiveconjugateaddition of acetone to nitroolefins
A series of bifunctional primary amine-thiophosphoramides were synthesized, which proven to be effective organocatalysts for the asymmetric Michael reaction of acetone to both aryl and alkyl nitro olefins in the presence of phenol as a protic additive. The corresponding adducts were obtained in excellent chemical yields (up to >99 %) with excellent enantioselectivities (up to 97 % ee).
Stereoselective Three‐Step One‐Pot Cascade Combining Amino‐ and Biocatalysis to Access Chiral γ‐Nitro Alcohols**
作者:Christian Ascaso‐Alegre、Raquel P. Herrera、Juan Mangas‐Sánchez
DOI:10.1002/anie.202209159
日期:2022.10.4
Chemoenzymatic cascades offer a simple and efficient way to rapidly build structural complexity. A three-step one-pot process is reported in which a Wittigreaction, chiral-thiourea-mediated asymmetric conjugate addition, and a bioreduction step were combined to access chiral nitro alcohols from commercially available benzaldehyde derivatives in good overall yields and excellent diastereomeric and