Hybrid-Type Squaramide-Fused Amino Alcohol Organocatalysts for Enantioselective Nitro-Aldol Reaction of Nitromethane with Isatins

A series of new hybrid type squaramide-fused amino alcohol (SFAA) catalysts were synthesized and their catalytic efficiency in enantioselective nitro-aldol reaction of various isatins with nitromethane that afford the chiral 3-substituted 3-hydroxyoxindoles in excellent chemical yields (up to 99%) and high enantioselectivities (up to 95% ee) is described. The resulting chiral 3-hydroxyoxindoles could be used as synthetic precursors for the synthesis of several natural products with a broad spectrum of fascinating biological activities

Chiral primary amino alcohol organobase catalyst for the asymmetric Diels-Alder reaction of anthrones with maleimides

Simple chiral TES-amino alcohol organocatalysts containing a bulkysilyl [triethylsilyl: TES] group on oxygen atom at γ-position were designed andsynthesized as new organocatalysts for the enantioselective Diels-Alder (DA) reactionof anthrones with maleimides to produce chiral hydroanthracene DA adducts (up to99% yield with up to 94% ee)

Catalytic Efficiency of Primary α-Amino Amides as Multifunctional Organocatalysts in Recent Asymmetric Organic Transformations

Chiral primary α-amino amides, consisting of an adjacent enamine bonding site (Bronsted base site), a hydrogen bonding site (Bronsted acid site), and flexible bulky substituent groups to modify the steric factor, are proving to be extremely valuable bifunctional organocatalysts for a wide range of asymmetric organic transformations. Primary α-amino amides are less expensive alternatives to other primary amino organocatalysts, such as chiral diamines and cinchona-alkaloid-derived primary amines, as they are easy to synthesize, air-stable, and allow for the incorporation of a variety of functional groups. In recent years, we have demonstrated the catalytic use of simple primary α-amino amides and their derivatives as organocatalysts for the aldol reaction, Strecker reaction, Michael tandem reaction, allylation of aldehydes, reduction of N-Aryl mines, opening of epoxides, hydrosilylation, asymmetric hydrogen transfer, and N-specific nitrosobenzene reaction with aldehydes

Catalytic Efficiency of Primary α-Amino Amides as Multifunctional Organocatalysts in Recent Asymmetric Organic Transformations

Chiral primary α-amino amides, consisting of an adjacent enamine bonding site (Bronsted base site), a hydrogen bonding site (Bronsted acid site), and flexible bulky substituent groups to modify the steric factor, are proving to be extremely valuable bifunctional organocatalysts for a wide range of asymmetric organic transformations. Primary α-amino amides are less expensive alternatives to other primary amino organocatalysts, such as chiral diamines and cinchona-alkaloid-derived primary amines, as they are easy to synthesize, air-stable, and allow for the incorporation of a variety of functional groups. In recent years, we have demonstrated the catalytic use of simple primary α-amino amides and their derivatives as organocatalysts for the aldol reaction, Strecker reaction, Michael tandem reaction, allylation of aldehydes, reduction of N-Aryl mines, opening of epoxides, hydrosilylation, asymmetric hydrogen transfer, and N-specific nitrosobenzene reaction with aldehydes

Hybrid-Type Squaramide-Fused Amino Alcohol Organocatalysts for Enantioselective Nitro-Aldol Reaction of Nitromethane with Isatins

application/pdfA series of new hybrid type squaramide-fused amino alcohol (SFAA) catalysts were synthesized and their catalytic efficiency in enantioselective nitro-aldol reaction of various isatins with nitromethane that afford the chiral 3-substituted 3-hydroxyoxindoles in excellent chemical yields (up to 99%) and high enantioselectivities (up to 95% ee) is described. The resulting chiral 3-hydroxyoxindoles could be used as synthetic precursors for the synthesis of several natural products with a broad spectrum of fascinating biological activities

Chiral primary amino alcohol organobase catalyst for the asymmetric Diels-Alder reaction of anthrones with maleimides

application/pdfSimple chiral TES-amino alcohol organocatalysts containing a bulky silyl [triethylsilyl: TES] group on oxygen atom at γ-position were designed and synthesized as new organocatalysts for the enantioselective Diels-Alder (DA) reaction of anthrones with maleimides to produce chiral hydroanthracene DA adducts (up to 99% yield with up to 94% ee)