1290608-24-0Relevant articles and documents
Synthesis of 6-nitro-1,2,3,4-tetrahydroquinoline: An experimental and theoretical study of regioselective nitration
Cordeiro, Alessandra,Shaw, Julian,O'Brien, John,Blanco, Fernando,Rozas, Isabel
, p. 1504 - 1513 (2011)
A revision of the literature on the nitration of tetrahydroquinolines yielded a number of inconsistencies. Thus, we have carried out a thorough study on the nitration of tetrahydroquinoline and several of its N-protected derivatives both experimentally and at theoretical level. Usually, nitration is carried out in acidic conditions and, thus, tetrahydroquinoline would be N-protonated; however, if the amino group is protected, the neutral system will be the one undergoing nitration. Different protecting groups have been explored varying, not only electronic and steric effects, but also deprotection conditions. Additionally, different reagents and reaction conditions have been investigated. From this study we have been able to achieve total regioselectivity for nitration at the 6-position. A very detailed NMR study has been carried out to unequivocally characterise the four nitro isomers. In parallel, a computational study has been performed that is in agreement with the experimental results obtained. With this purpose, all the σ complexes of the four nitro isomers neutral and N-protonated have been optimized both in gas and water condensed phases by using the B3LYP/6-31++G* level of computation. The selective nitration of tetrahydroquinoline was studied. N-Protecting groups presence or absence directs nitration at different positions. Regioselective nitration at 6-position was achieved. A DFT computational study of all nitro σ complexes was performed in gas and water phases, the results are consistent with the experiments. Copyright
Regioselective Functionalization of 9,9-Dimethyl-9-silafluorenes by Borylation, Bromination, and Nitration
Murai, Masahito,Nishinaka, Naoki,Kimura, Mizuki,Takai, Kazuhiko
, (2019/05/08)
Despite the utility of 9-silafluorenes as functional materials and as building blocks, methods for efficient functionalization of their backbone are rare, probably because of the presence of easily cleavable C-Si bonds. Although controlling the regioselectivity of iridium-catalyzed direct borylation of C-H bonds is difficult, we found that bromination and nitration of 2-methoxy-9-silafluorene under mild conditions occurred predominantly at the electron-rich position. The resulting product having methoxy and bromo groups can be utilized as a building block for the synthesis of unsymmetrically substituted 9-silafluorene-containing π-conjugated molecules.
