Pd-catalyzed asymmetric hydrogenation of fluorinated aromatic pyrazol-5-ols via capture of active tautomers.

Pd-catalyzed asymmetric hydrogenation of fluorinated aromatic pyrazol-5-ols via capture of active tautomers† †Electronic supplementary information (ESI) available. CCDC 1040656–1040658. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5sc00835b Click here for additional data file. Click here for additional data file.

Synthesis of 4,4´-(Arylmethylene)bis(1H-pyrazol-5-ols) catalyzed by nanosilica supported perchloric acid in water

Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.

Synthesis of 4,4´-(Arylmethylene)bis(1H-pyrazol-5-ols) catalyzed by nanosilica supported perchloric acid in water

Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.

Synthesis of Chiral Fluorinated Hydrazines via Pd-Catalyzed Asymmetric Hydrogenation.

An enantioselective hydrogenation of fluorinated hydrazones has been achieved by employing [Pd(R)-DTBM-SegPhos(OCOCF3)2] as the catalyst, providing a general and convenient method toward chiral fluorinated hydrazines. A broad substrate scope including β-aryl-, γ-aryl-, and alkyl-chain-substituted hydrazones worked efficiently in high yields and up to 94% of enantioselectivity. The reductive ami...

Asymmetric hydrogenation via capture of active intermediates generated from aza-Pinacol rearrangement.

An efficient palladium-catalyzed asymmetric hydrogenation via capture of an active intermediate generated in situ from acid-catalyzed aza-Pinacol rearrangement has been successfully developed, providing efficient access to chiral exocyclic amines with up to 98% ee. Three-, four-, and five-membered cyclic N-sulfonyl amino alcohols are viable substrates. This study opens a new window to the appli...