meso-Functionalized dipyrromethanes 6-10 were synthesized by acid-catalyzed addition of pyrrole to αposition of 2-alkenyl pyrroles. The regiochemistry of the reaction can be explained by either the formation of more stable carbocation intermediate or β-addition of α,β-unsaturated carbonyl compounds. The starting 2alkenyl pyrroles were synthesized by Aldol condensation of 2-formylpyrrole with ac...

An ytterbium catalyzed formal [3+3] cycloaddition of cyclic enamines and ?,?-unsaturated ketones is reported. The reaction proceeds with a ‘head to tail’ regioselectivity through conjugate addition the enamine moiety followed by an amine-carbonyl condensation. In use chiral provided high degree stereoselectivity, driven possible balance between steric ?-stacking effects. resulting bicyclic 1,4-...

Selective hydrogenation of the carbon-oxygen bond in α,β-unsaturated carbonyl compounds is a synthetic challenge, since C=C bond reduction is thermodynamically more favorable (35 kJ mol–1) than C=O bond reduction.[1] This problem becomes even more complicated by the presence of an aromatic substituent in such systems because of possible ring hydrogenation.[2] Moreover, the transformation of uns...

The effect of Maillard reaction on red blood cells (RBC) deformability was investigated. Exposure of RBC to carbonyl compounds (dl-glyceraldehyde, glyoxal, glycolaldehyde, 3-deoxyglucosone, and d-glucose) leading to Maillard reaction caused a marked decrease in RBC deformability even at 1mM level. The decrease rate depended on the kind of carbonyl compounds, in which both dl-glyceraldehyde and ...

silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.