Photoreactions of biacetyl and tetramethylethylene. Solvent and temperature effects

The photoreaction of biacetyl and tetramethylethylene yields four products (1–4). A substantial variation in product yield and quenching kinetics with temperature and isotopic substitution is found for this photoreaction.     

Integral and state-to-state cross sections for the reaction D + H2(νf) → HD(νf) + H: A quantum mechanical study within the infinite order sudden approximation

In this paper are presented quantum mechanical t-initial and t-average cross sections and rate constants for the reactions D + H₂(ν₁ = 0, 1) → HD(ν_f = 0, 1) + H. The calculations were done employing the infinite order sudden approximation. It was found that the t-average total cross sections overlap very nicely with the available classical cross sections. As for rate constants a reasonably good fit was found with available experimental results.     

Synthesis of novel 1,4-, 3,4-, and 4,5-dihydropyrimidines: First successful POCl3 chlorination and regioselective alkoxycarbonylation

Chlorination of 5,6-dihydropyrimidine-4-(3H)-one derivatives (1) with POCl₃ gave 1,4(3,4)-dihydropyrimidines (3), whose alkoxycarbonylation (ClCOOREt₃N or NaH) afforded regioselectively novel compounds (4). A new Pummerer rearrangement of compound (1, X= ---S(O)CH₃) with ₃, gave compound (5h).     

Ammonium chloride-catalyzed green multicomponent synthesis of dihydropyrazine and tetrahydrodiazepine derivatives “on water”

Molecular Diversity - This research describes a simple and efficient one-pot synthetic approach for the preparation of tetrahydrodiazepine and dihydropyrazine (or dihydroquinoxaline) derivatives in...