75997-19-2Relevant academic research and scientific papers
The Synthesis of 1H- and 5H-Thienodiazepines by the Electrocyclisation of α-(2-Alkenylthienyl)diazoalkanes, and Some Observations on their Photochemical Reactivity and Ring Inverison
Munro, David P.,Sharp, John T.
, p. 1718 - 1723 (2007/10/02)
The cyclisation of the α-(2-alkenylthienyl)diazoalkanes (4) and (5) provides the first route to thieno- and thieno-diazepines, (10) and (11) respectively.In contrast, 3-diazomethyl-4-(trans-2-phenylethenyl)thiophen (6) did not cyclise but gave carbene-derived products.The thienodiazepines (10) and (11) were converted by base into the isomeric thieno-diazepines (15) and (16) respectively and by u.v. irradiation into the diazetothienopyrroles (21) and (22).Variable-temperature proton n.m.r. studies have shown that the energy barrier to ring inversion is lower for the thienodiazepines than for analogous benzodiazepines.
