181260-35-5

Upstream product

• 459-57-4 4-fluorobenzaldehyde 
• 91-00-9 Benzhydrylamine 
• 456-22-4 4-Fluorobenzoic acid 
• 88229-31-6 (4-Fluorobenzoylamino)diphenylmethane 

Downstream Products

• 125553-06-2 α-amino-(4'-fluorophenyl-)methanephosphonic acid 
• 1282607-15-1 (-)-N-benzhydryl(diphenylphosphoryl)(4-fluorophenyl)methanamine 

Relevant academic research and scientific papers

Enantioselective Reductive Cyanation and Phosphonylation of Secondary Amides by Iridium and Chiral Thiourea Sequential Catalysis

The combination of transition-metal catalysis and organocatalysis increasingly offers chemists opportunities to realize diverse unprecedented chemical transformations. By combining iridium with chiral thiourea catalysis, direct enantioselective reductive cyanation and phosphonylation of secondary amides have been accomplished for the first time for the synthesis of enantioenriched chiral α-aminonitriles and α-aminophosphonates. The protocol is highly efficient and enantioselective, providing a novel route to the synthesis of optically active α-functionalized amines from the simple, readily available feedstocks. In addition, the reactions are scalable and the thiourea catalyst can be recycled and reused.

Diastereoselective and Enantiospecific Synthesis of 1,3-Diamines via 2-Azaallyl Anion Benzylic Ring-Opening of Aziridines

The 1,3-diamine motif appears in numerous complex molecules, yet there are few methods for the stereoselective construction of this moiety. Herein, we demonstrate a stereocontrolled synthesis of 1,3-diamines, which bear up to three contiguous stereogenic centers, through benzylic ring-opening of aziridines with 2-azaallyl anion nucleophiles. Reactions proceed efficiently (yield up to 95%), diastereoselectively (dr up to >20:1), site selectively, and enantiospecifically to deliver products with differentiated amino groups.

Access to α-Arylglycines by Umpolung Carboxylation of Aromatic Imines with Carbon Dioxide

A straightforward and transition-metal-free approach for the efficient synthesis of α-arylglycine derivatives from aromatic imines and carbon dioxide was enabled by an umpolung carboxylation reaction. Various substituted diphenylmethimines underwent the carboxylation smoothly with carbon dioxide in the presence of potassium tert-butoxide and 18-crown-6 to give the corresponding carboxylated products in good to high yields. Besides the enhancement of the solubility of potassium tert-butoxide in THF, 18-crown-6 also plays key roles in suppressing the reverse protonation or 1, 3-proton shift isomerization as well as by stabilizing the carboxylated intermediate.

A remarkable titanium-catalyzed asymmetric strecker reaction using hydrogen cyanide at room temperature

Close to perfect enantioselectivity (up to 98% ee) is obtained for the formation of amino nitrites using hydrogen cyanide (HCN) as the cyanide source at room temperature for the first time. In an operationally simple process, the catalyst generated from a partially hydrolyzed titanium alkoxide (PHTA) and (S)-N-salicyl-ss-amino alcohol ligand, catalyzes the cyanation of imines in a short reaction time.

The preparation and characterization of some fluorinated α-aminoarylmethanephosphonic acids

α-Aminoarylmethanephosphonic acids have been prepared with a range of fluoro, fluoroalkyl, or fluoroalkoxy substituents in the benzene ring (4-F, 3-F, 2-F, 3,4-F2, F5, 4-CF3, 3-CF3, 4-CF3O, and 3-CF3O). These compounds have relatively low aqueous solubility and their NMR spectra (1H, 13C, 31P and 19F) were therefore recorded in D2O in the presence of an excess of alkali. Under these conditions, the ring substituents appear to have little effect on δp (15-18 ppm), or on the 1H and 13C parameters for the benzylic group (α-CH), which are mainly in the ranges observed for other types of α-aminoarylmethanephosphonic acids under alkaline conditions (δH 3.8-4.0 ppm, 2JPH 15.3-16.5 Hz; δC 57-58 ppm, 1JPC 128-132 Hz). For those examples with fluorine in the ortho position (i.e., the 2-fluoro and pentafluoro derivatives) a slightly higher field chemical shift was observed for the benzylic carbon atom (δC 50-51 ppm). In the fast-atom bombardment mass spectra, pseudo-molecular ions, MH+, and ions resulting from the elimination of phosphorous acid [MH - H3PO3]+, provide a further useful means of chararacterization for these compounds. Key words: Fluorinated aminoarylmethanephosphonic acids, dialkyl N-diphenylmethylaminoaryl-methanephosphonates, NMR spectroscopy, FAB mass spectrometry.