Bifunctional Amine-thiourea Catalyst Research Articles

Organocatalytic Asymmetric Decarboxylative Mannich Reaction of β-Keto Acids with Cyclic α-Ketiminophosphonates: Access to Quaternary α-Aminophosphonates.

An organocatalytic asymmetric decarboxylative Mannich reaction of β-keto acids with cyclic α-ketiminophosphonates has been developed. By using saccharide-derived bifunctional amine-thiourea catalysts bearing an axial chiral binaphthyl scaffold, a wide range of quaternary α-amino-γ-oxophosphonates were obtained in up to 93% yield and >99% ee. Furthermore, two interesting α-aminophosphonate derivatives were synthesized from the corresponding decarboxylative Mannich product via simple transformations.

Remote Asymmetric Oxa-Diels-Alder Reaction of 5-Allylic Furfurals via Dearomatizative Tetraenamine Catalysis.

A previously unreported activation mode is developed through the generation of dearomatizative tetraenamine species between 5-allylic furfurals and a bifunctional amine-thiourea catalyst. The very remote ζ,η-alkenes perform as effective HOMO-raised dienophiles in inverse-electron-demand oxa-Diels-Alder cycloadditions with isatin-derived oxadiene substrates, delivering multifunctional spirocyclic oxindoles incorporating a dihydropyran skeleton in moderate to high yields with good to excellent enantio- and diastereoselectivity.

Catalytic Asymmetric Desymmetrization of Cyclopentendiones via Diels-Alder Reaction of 3-Hydroxy-2-pyrones: Construction of Multifunctional Bridged Tricyclic Lactones.

An unprecedented asymmetric Diels-Alder reaction of 3-hydroxy-2-pyrones with prochiral cyclopentene-1,3-diones via desymmetrization was efficiently realized with high stereoselective control with the aid of fine-tunable cinchona alkaloid derived bifunctional amine-thiourea catalysts bearing multiple hydrogen-bonding donors. This protocol provides an expedient access to the multifunctional-bridged tricyclic lactones featuring four contiguous stereogenic centers and one remote quaternary stereogenic center with a broad substrate scope. The cycloadduct can be readily elaborated into enantioenriched cyclopentane-1,3-diones via ring opening/aromatization.

Organocatalytic asymmetric Henry reaction of 1H-pyrrole-2,3-diones with bifunctional amine-thiourea catalysts bearing multiple hydrogen-bond donors.

For the first time, a catalytic asymmetric Henry reaction of 1H-pyrrole-2,3-diones was achieved with a chiral bifunctional amine-thiourea as a catalyst possessing multiple hydrogen-bond donors. With this developed method, a range of 3-hydroxy-3-nitromethyl-1H-pyrrol-2(3H)-ones bearing quaternary stereocenters were obtained in acceptable yield (up to 75%) and enantioselectivity (up to 73% ee).

Asymmetric Michael reaction of arylacetyl phosphonates to nitroalkenes with bifunctional amine-thiourea catalyst bearing multiple-hydrogen-bond donor: efficient construction of chiral α-substituted carboxylic ester compounds

Catalytic asymmetric Michael addition of arylacetyl phosphonates to nitroalkenes was achieved with a chiral bifunctional amine-thiourea bearing a multiple-hydrogen-bond donor as a catalyst. A range of α-substituted carboxylic ester compounds with contiguous tertiary stereocenters could be smoothly obtained in good yields (up to 85%) and with high to excellent diastereo- and enantioselectivities (up to >99:1 dr and 95% ee). The large scale experiment and facile synthesis of a chiral γ-butyrolactam have also been demonstrated.

Enantioselective Sulfur‐Michael Addition of Thioacetic Acid to Nitroalkenes Catalyzed by Bifunctional Amine‐Thiourea Catalysts

AbstractAn enantioselective Michael addition of thioacetic acid (AcSH) to nitroalkenes, catalyzed by a leucine‐derived bifunctional aminethiourea, was developed with high yields and moderate enantioselectivities. The thiourea‐ammonium salt formed in the reaction is identified as the active catalyst, and the multiple H‐bonding system is responsible for the stereocontrol. The resulting thioester products are useful intermediates for the synthesis of enantiomerically enriched S‐containing compounds.

Organocatalytic asymmetric sulfa-Michael addition of thiols to trans-3,3,3-trifluoropropenyl phenyl sulfone

The first asymmetric sulfa-Michael addition of thiols to trans -3,3,3-trifluoropropenyl phenyl sulfone for the construction of a unique stereogenic center bearing a trifluoromethyl group and a sulfur atom has been achieved in high yields and moderate to good enantioselectivities with 1 mol % bifunctional amine–thiourea catalyst. The first asymmetric sulfa-Michael addition of thiols to trans -3,3,3-trifluoropropenyl phenyl sulfone for the construction of a unique stereogenic center bearing a trifluoromethyl group and a sulfur atom has been achieved in high yields and moderate to good enantioselectivities with 1 mol % bifunctional amine–thiourea catalyst.

ChemInform Abstract: Highly Enantioselective Epoxidation Catalyzed by Cinchona Thioureas: Synthesis of Functionalized Terminal Epoxides Bearing a Quaternary Stereogenic Center.

AbstractThe asymmetric epoxidation of electron‐poor terminal alkenes is efficiently catalyzed by quinine‐derived bifunctional amine—thiourea catalysts.

ChemInform Abstract: Catalytic Enantioselective Addition of Sodium Bisulfite to Chalcones.

AbstractAsymmetric addition of sodium bisulfite towards chalcone derivatives (I) is efficiently catalyzed by a cinchona alkaloid‐derived bifunctional amine—thiourea catalyst.

ChemInform Abstract: Chiral Bifunctional Thiourea‐Catalyzed Enantioselective Aldol Reaction of Trifluoroacetaldehyde Hemiacetal with Aromatic Ketones.

Abstract In the presence of saccharide-derived bifunctional amine-thiourea catalysts, the direct aldol condensation of trifluoroacetaldehyde methyl hemiacetal with aromatic ketones proceeds to produce ( R )-β-hydroxy β-trifluoroalkyl ketones in low to moderate yields with good enantioselectivities.

Chiral bifunctional thiourea-catalyzed enantioselective aldol reaction of trifluoroacetaldehyde hemiacetal with aromatic ketones

In the presence of saccharide-derived bifunctional amine-thiourea catalysts, the direct aldol condensation of trifluoroacetaldehyde methyl hemiacetal with aromatic ketones proceeds to produce ( R)-β-hydroxy β-trifluoroalkyl ketones in low to moderate yields with good enantioselectivities.

ChemInform Abstract: Enantioselective Synthesis of Coumarins Catalyzed by a Bifunctional Amine—Thiourea Catalyst.

ChemInform Abstract: Enantioselective Synthesis of Coumarins Catalyzed by a Bifunctional Amine—Thiourea Catalyst.

Enantioselective Synthesis of Coumarins Catalyzed by a Bifunctional Amine–Thiourea Catalyst

Efficient excess: An efficient and facile enantioselective Michael addition reaction through hydrogen-bonding catalysis for the synthesis of coumarin complexes has been developed (see scheme). A simple bifunctional amine–thiourea small molecule has been discovered to catalyze this process with high yields and high to excellent enantiomeric excesses. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Highly Enantioselective Direct Michael Addition of Nitroalkanes to Nitroalkenes Catalyzed by Amine−Thiourea Bearing Multiple Hydrogen-Bonding Donors

A highly diastereoselective and enantioselective Michael addition of nitroalkanes to nitroalkenes has been achieved by chiral bifunctional amine-thiourea catalyst bearing multiple hydrogen-bonding donors. This catalytic system performs well over a broad scope of substrates, furnishing various 1,3-dinitro compounds in high diastereoselectivity (up to 98:2) and excellent enantioselectivity (up to 99% ee) under mild conditions. Multiple hydrogen bonding donors play a significant role in accelerating reactions, improving diastereoselectivities and enantioselectivities.