Synthesis and structure of some azo coupled cyclic beta-enaminones

Synthesis of fused-tetrahydropyrimidines: one-pot methylenation–cyclization utilizing two molecules of CO2

A methylenation–cyclization reaction employing cyclic enaminones with primary aromatic amines and two molecules of CO₂ to furnish fused-tetrahydropyrimidines has been developed.

Study of E/Z isomerization of (arylamino)methylidenefuran-2(3H)-ones by 1 H, 13 C, 15 N spectroscopy and DFT calculations in different solvents

The structure and configuration of the series of previously unknown arylaminomethylidenefuran-2(3H)-ones have been determined in solution by ¹ H, ¹³ C, ¹⁵ N nuclear magnetic resonance spectroscopy including two-dimensional experiments such as ¹ H─¹ H COSY, dqCOSY, ¹ H─¹³ C HSQC, ¹ H─¹³ C HMBC. It was found that synthesized substances exist as an equilibrium mixture of E- and Z-enamines in solution. It was established on the basis of density functional theory calculations that the exchange between the two push-pull enamines is a simple rotation around an exocyclic partial double bond that depends on the effect of the solvents. Copyright © 2017 John Wiley & Sons, Ltd.