Berthiaume, Sylvie L.; Bray, Brian L.; Hess, Petr; Liu, Yanzhou; Maddox, Michael L.; Muchowski, Joseph M.; Scheller, Markus E. published the artcile< Synthesis of 5-substituted pyrrole-2-carboxaldehydes. Part I. Generation of formal 5-lithiopyrrole-2-carboxaldehyde equivalents by bromine-lithium exchange of 2-bromo-6-(diisopropylamino)-1-azafulvene derivatives>, Formula: C8H9NO3, the main research area is azafulvene lithiated derivative; pyrrolecarboxaldehyde derivative.
The first known lithiated 1-azafulvene derivatives, e.g., I, were generated by a low-temperature bromine-lithium exchange procedure with tert-butyllithium. These lithio species show substantial stability at ≤-90°C because, at these temperatures, the sterically demanding 6-diisopropylamino moiety, unlike the dimethylamino group, completely inhibits nucleophilic addition to C-6. At higher temperatures, the addition of tert-butyllithium to C-6 is significant and it can become the dominant process. The lithio species I is a useful formal equivalent of 5-lithiopyrrole-2-carboxaldehyde since, on reaction with electrophilic reagents and subsequent hydrolysis, a wide variety of regiochem. pure 5-substituted pyrrole-2-carboxaldehydes is formed. The 6-dialkylamino-1-azafulvenes described herein exist predominantly or exclusively as the syn conformer in solution at room temperature This conformational preference is confirmed by a significant NOE effect between H-4 and H-6 in the parent diisopropylamino-substituted azafulvene. The origin of the syn conformational preference stems from a substantial contribution of the charge-separated form to the ground state structure of these compounds, a phenomenon that is strongly supported by variable temperature NMR measurements on 2-bromo-6-diisopropylamino-1-azafulvene.
Canadian Journal of Chemistry published new progress about Lithiation. 7126-50-3 belongs to class esters-buliding-blocks, and the molecular formula is C8H9NO3, Formula: C8H9NO3.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics