1644384-68-8Relevant academic research and scientific papers
Practical Continuous-Flow Trapping Metalations of Functionalized Arenes and Heteroarenes Using TMPLi in the Presence of Mg, Zn, Cu, or la Halides
Becker, Matthias R.,Knochel, Paul
supporting information, p. 12501 - 12505 (2015/10/12)
The flow metalation of various arenes and heteroarenes involving an in situ trapping with metal salts (ZnCl2. LiCl, MgCl2, CuCN. LiCl, LaCl3. LiCl) under very convenient conditions (0 ?C, 40 s) is reported. The resulting Mg, Zn, Cu, or La organic species are trapped with various electrophiles in high yields. In several cases, unusual kinetically controlled regioselectivities are obtained. All these flow metalations can be scaled up simply by extending the reaction time and without further optimization. The reaction scope of such flow metalations is considerably broader than that of the corresponding batch procedures.
New in situ trapping metalations of functionalized arenes and heteroarenes with TMPLi in the presence of ZnCl2 and other metal salts
Frischmuth, Annette,Fernandez, Maitane,Barl, Nadja M.,Achrainer, Florian,Zipse, Hendrik,Berionni, Guillaume,Mayr, Herbert,Karaghiosoff, Konstantin,Knochel, Paul
supporting information, p. 7928 - 7932 (2014/08/05)
The addition of TMPLi to a mixture of an aromatic or heteroaromatic substrate with a metal salt such as MgCl2, ZnCl2, or CuCN at -78 °C first leads to lithiation of the arene followed by transmetalation with the metal salt to afford functionalized organometallic compounds of Mg, Zn, or Cu. This in situ trapping method allows an expedited metalation (-78 °C, 5 min) of a range of sensitive pyridines (bearing a nitro, ester, or cyano group) and allows the preparation of kinetic regioisomers of functionalized aromatic compounds or heterocycles not otherwise available by standard metalating agents, such as TMPMgCl·LiCl or TMPZnCl·LiCl. Fast, faster, the fastest: Aromatic and heterocyclic substrates, when treated with TMPLi (TMP=2,2,6,6-tetramethylpiperidyl), undergo a kinetic lithiation and then a transmetalation with a metal salt such as MgCl2, ZnCl 2, or CuCN. This allows an expedited metalation of sensitive pyridines bearing a nitro, ester, or cyano group and allows the preparation of kinetic regioisomers of functionalized aromatic compounds or heterocycles.
