Leroux Baptiste, Beaufils Alexis, Banchini Federico, Jackowski Olivier, Perez-Luna Alejandro, Chemla Fabrice, Presset Marc, Le Gall Erwan
Univ Paris-Est Créteil, CNRS, ICMPE, UMR 7182, 2 rue Henri Dunant, 94320 Thiais, France.
Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, 75005 Paris, France.
Beilstein J Org Chem. 2024 Nov 7;20:2834-2839. doi: 10.3762/bjoc.20.239. eCollection 2024.
The use of alkylzinc bromides in the multicomponent Mannich reaction is described. Heteroleptic organozinc compounds were obtained in THF or 2-MeTHF by direct insertion of zinc dust into the C-Br bond of alkyl bromides. It was found that the presence of a stoichiometric amount of LiCl was essential for the efficiency of the subsequent three-component coupling with aldehydes and amines. A variety of primary, secondary, and tertiary organozinc reagents as well as secondary amines and aromatic aldehydes could be used for the straightforward preparation of α-branched amines. Interestingly, whereas previously reported work describing the preparation and reaction of organozinc iodides in acetonitrile showed higher reactivity of secondary organozinc reagents over primary ones, reactions in THF in the presence of LiCl led to opposite results, with higher reactivity of primary organozinc reagents.
本文描述了烷基溴化锌在多组分曼尼希反应中的应用。通过将锌粉直接插入烷基溴的C-Br键中，在四氢呋喃（THF）或2-甲基四氢呋喃（2-MeTHF）中制备了杂配有机锌化合物。结果发现，化学计量的LiCl对于随后与醛和胺进行的三组分偶联反应的效率至关重要。各种伯、仲和叔有机锌试剂以及仲胺和芳香醛可用于直接制备α-支链胺。有趣的是，尽管先前报道的关于在乙腈中制备和反应有机碘化锌的工作表明仲有机锌试剂比伯有机锌试剂具有更高的反应活性，但在LiCl存在下于THF中进行的反应却得到了相反的结果，即伯有机锌试剂具有更高的反应活性。
