Intermolecular Tandem Addition−Cyclization of Bromoallenes: A Facile Synthesis of Methylenecyclopropyl Carboxylates and Polysubstituted Furans

The base-mediated reactions of 1,3-dicarbonyl compounds with bromoallenes used as an allyl dication equivalent were explored. The corresponding dimethyl methylenecyclopropane-1,1-dicarboxylates and 2,3,4-trisubstituted furans were efficiently synthesized

Intermolecular Tandem Addition−Cyclization of Bromoallenes: A Facile Synthesis of Methylenecyclopropyl Carboxylates and Polysubstituted Furans

The base-mediated reactions of 1,3-dicarbonyl compounds with bromoallenes used as an allyl dication equivalent were explored. The corresponding dimethyl methylenecyclopropane-1,1-dicarboxylates and 2,3,4-trisubstituted furans were efficiently synthesized

Intermolecular Tandem Addition−Cyclization of Bromoallenes: A Facile Synthesis of Methylenecyclopropyl Carboxylates and Polysubstituted Furans

The base-mediated reactions of 1,3-dicarbonyl compounds with bromoallenes used as an allyl dication equivalent were explored. The corresponding dimethyl methylenecyclopropane-1,1-dicarboxylates and 2,3,4-trisubstituted furans were efficiently synthesized

Highly Enantioselective and Regioselective Substitution of Morita–Baylis–Hillman Carbonates with Nitroalkanes

A highly enantioselective and regioselective substitution reaction of the Morita–Baylis–Hillman (MBH) carbonates with nitroalkanes catalyzed by a quinidine-derived tertiary amine–thiourea catalyst has been developed. The described method, which is different from most organocatalytic allylic substitutions of the MBH adducts to date, represents a novel approach to regioselectively functionalize the MBH adducts

Highly Enantioselective and Regioselective Substitution of Morita–Baylis–Hillman Carbonates with Nitroalkanes

A highly enantioselective and regioselective substitution reaction of the Morita–Baylis–Hillman (MBH) carbonates with nitroalkanes catalyzed by a quinidine-derived tertiary amine–thiourea catalyst has been developed. The described method, which is different from most organocatalytic allylic substitutions of the MBH adducts to date, represents a novel approach to regioselectively functionalize the MBH adducts

Asymmetric Allylic Alkylation of Isatin-Derived Morita–Baylis–Hillman Carbonates with Nitroalkanes

A stereoselective allylic alkylation of isatin-derived Morita–Baylis–Hillman (MBH) carbonates with nitroalkanes has been developed. In the presence of 10 mol % β-isocupreidine (β-ICD), 3,3′-disubstituted oxindoles were prepared with moderate diastereoselectivities and excellent enantioselectivities

Enantioselective Morita−Baylis−Hillman Reaction of Isatins with Acrylates: Facile Creation of 3-Hydroxy-2-oxindoles

The first tertiary amine catalyzed enantioselective Morita−Baylis−Hillman (MBH) reaction of isatins with acrylates has been demonstrated, allowing asymmetric synthesis of biologically significant 3-substituted-3-hydroxy-2-oxindoles in good yields and with excellent enantioselectivities. The C6′−OH group of β-isocupreidine (β-ICD) is believed to facilitate the key proton transfer step in the MBH reaction, via an intramolecular proton relay process

Enantioselective Morita−Baylis−Hillman Reaction of Isatins with Acrylates: Facile Creation of 3-Hydroxy-2-oxindoles

The first tertiary amine catalyzed enantioselective Morita−Baylis−Hillman (MBH) reaction of isatins with acrylates has been demonstrated, allowing asymmetric synthesis of biologically significant 3-substituted-3-hydroxy-2-oxindoles in good yields and with excellent enantioselectivities. The C6′−OH group of β-isocupreidine (β-ICD) is believed to facilitate the key proton transfer step in the MBH reaction, via an intramolecular proton relay process

Enantioselective [3 + 2] Cycloaddition of Allenes to Acrylates Catalyzed by Dipeptide-Derived Phosphines: Facile Creation of Functionalized Cyclopentenes Containing Quaternary Stereogenic Centers

A new family of dipeptide-based chiral phosphines was designed and prepared. d-Thr-l-tert-Leu-derived catalyst 4c promoted [3 + 2] cycloaddition of allenoates to α-substituted acrylates in a regiospecific and stereoselective manner, furnishing functionalized cyclopentenes with quaternary stereogenic centers in high yields and with excellent enantioselectivities

Enantioselective [3 + 2] Cycloaddition of Allenes to Acrylates Catalyzed by Dipeptide-Derived Phosphines: Facile Creation of Functionalized Cyclopentenes Containing Quaternary Stereogenic Centers

A new family of dipeptide-based chiral phosphines was designed and prepared. d-Thr-l-tert-Leu-derived catalyst 4c promoted [3 + 2] cycloaddition of allenoates to α-substituted acrylates in a regiospecific and stereoselective manner, furnishing functionalized cyclopentenes with quaternary stereogenic centers in high yields and with excellent enantioselectivities