Dynamic kinetic Transfer hydrogenation reaction of 2-methyl-2,4-diaryl-2,3-dihydrobenzo[b][1,4]diazepines, using phosphoric acids as catalysts and Hantzsch ester as hydride source, has been studied. A 3,3'-H8-binol derived phosphoric acid has been identified the optimal chiral catalyst for this transformation, affording 1,3-diamine derivatives with up to 8/1 dr, 86% ee and 94% ee for the major ...

addition of potassium cyanide to a mixture of schiff base and lithium perchlorate afforded a-aminonitriles in high yields. addition of potassium cyanide to a methanolic solution of schiff base and phosphoric acid afforded a-aminonitriles. when the reaction mixture was refluxed it gave a-amino acids in high yields.

The first highly enantioselective iso-Pictet-Spengler reaction of C-2-linked o-aminobenzylindoles with trifluoromethyl ketones was developed using chiral spirocyclic phosphoric acids as organocatalysts, which afforded optically active benzazepinoindoles bearing trifluoromethylated quaternary stereocenters.

The effect of two acids (phosphoric and acetic) and their derivatives (hydrogen di(2-ethylhexyl)orthophosphoric, chloroacetic, dichloroacetic, trichloroacetic, and trifluoroacetic acids) on the retention of selected alkaloids on silica gel plates has been investigated. The dependence of the chromatographic behaviour of the alkaloids on mobile phase diluent and on the concentration of the acids ...

Cyclic phosphoric acids displaying planar chiral paracyclophane structures, which include a 1,1'-ferrocenediyl unit, have been designed as a new class of chiral organocatalysts. Their synthesis, optical resolution, structural characterization and preliminary catalytic tests are reported.