Reduction of hydrazines to amines with low-valent titanium reagent
作者:Fang Ren、Yan Zhang、Lan Hu、Meiming Luo
DOI:10.3998/ark.5550190.0014.313
日期:——
The N,N bond cleavage in hydrazines to amines via low-valenttitaniumreagent prepared in situ by treatment of TiCl4 with Mg powder in THF or CH2Cl2-Et2O is described. The reaction proceeds smoothly under mild conditions to afford amines in good to excellent yields with diverse functional group tolerance such as chloride, methoxyl, benzyloxyl, ester, acyl, as well as C,C double bonds and benzyl-nitrogen
Reduction of hydrazines to amines with aqueous solution of titanium(iii) trichloride
作者:Yan Zhang、Qiang Tang、Meiming Luo
DOI:10.1039/c1ob05328k
日期:——
cleavage in hydrazines is widely used in the preparation of amines and thus occupies a significant place in organic synthesis. In this paper, we report a new method for the reductive cleavage of N–N bonds in hydrazines by commercially available and cheap aqueous titanium(III) trichloride. The reaction proceeds smoothly under a broad pH range from acidic to neutral and basic conditions to afford amines in good
Direct<i>ortho</i>-Selective Amination of 2-Naphthol and Its Analogues with Hydrazines
作者:Lei Jia、Qiang Tang、Meiming Luo、Xiaoming Zeng
DOI:10.1021/acs.joc.8b00421
日期:2018.5.4
is a regioselective ortho-amination of 2-naphthol and its analogues with substituted hydrazines. It provides a direct methodology for the synthesis of N-arylaminated naphthol derivatives without the formation of related 1,1′-biaryl-2,2′-diamine or carbazole byproducts. Specifically, using N,N-disubstituted hydrazine precursors, N-unsubstituted ortho-aminated derivatives and related secondary amines
strong bases (n-BuLi, s-BuLi/TMEDA, n-BuLi/t-BuOK, TMPMgCl·LiCl, and LDA) reduce the N═N bond of the parent azobenzene (Y = H), aromatic H→Li permutation occurs with LTMP when a suitable director of lithiation (Y = OMe, CONEt2, F) is present in the benzene residue of the azo compound. The method allows direct access to new substituted azobenzenes.
Synthesis of trisubstituted hydrazine <i>via</i> MnO<sub>2</sub>-promoted oxidative coupling of <i>N</i>,<i>N</i>-disubstituted hydrazine and boronic ester
作者:Jiaoyang Wang、Danfeng Wang、Xiaofeng Tong
DOI:10.1039/d1ob00929j
日期:——
oxidative coupling process between N,N-disubstituted hydrazine and boronic ester is reported. A 1,1-diazene species is firstly generated upon oxidation of a hydrazine substrate in the presence of MnO2 which then interacts with boronic ester to form the key intermediate boron-ate complex, followed by migration from boron to nitrogen to form a new C–N bond. This new finding provides mild, scalable, and
报道了MnO 2促进的N,N-二取代肼和硼酸酯之间的氧化偶联过程。首先在 MnO 2存在下氧化肼底物产生 1,1-二氮烯物种,然后与硼酸酯相互作用形成关键的中间体硼酸酯复合物,然后从硼迁移到氮形成新的 C -N 键。这一新发现提供了对三取代肼的温和、可扩展且操作简单的途径。