TITANIUM (IV) COMPOUNDS AND METHODS OF FORMING HETEROCYCLIC COMPOUNDS USING SAME
申请人:REGENTS OF THE UNIVERSITY OF MINNESOTA
公开号:US20160200746A1
公开(公告)日:2016-07-14
The present disclosure provides Titanium (IV) compounds and methods of making heterocyclic compounds such as pyrroles using Titanium (IV) compounds. In certain embodiments, the Titanium (IV) compound is present in catalytic amounts.
Oxidative nitrene transfer from azides to alkynes <i>via</i> Ti(<scp>ii</scp>)/Ti(<scp>iv</scp>) redox catalysis: formal [2+2+1] synthesis of pyrroles
作者:Adam J. Pearce、Xin Yi See、Ian A. Tonks
DOI:10.1039/c8cc02623h
日期:——
Catalytic oxidative nitrene transfer from azides with the early transition metals is rare, and has not been observed without the support of redox noninnocent spectator ligands.
Catalytic formal [2+2+1] synthesis of pyrroles from alkynes and diazenes via TiII/TiIV redox catalysis
作者:Zachary W. Gilbert、Ryan J. Hue、Ian A. Tonks
DOI:10.1038/nchem.2386
日期:2016.1
Pyrroles are structurally important heterocycles. However, the synthesis of polysubstitutedpyrroles is often challenging. Here, we report a multicomponent, Ti-catalysed formal [2+2+1] reaction of alkynes and diazenes for the oxidative synthesis of penta- and trisubstituted pyrroles: a nitrenoid analogue to classical Pauson–Khand-type syntheses of cyclopentenones. Given the scarcity of early transition-metal
吡咯是结构上重要的杂环。然而,多取代的吡咯的合成通常具有挑战性。在这里,我们报道了炔烃和二烯的多组分,钛催化的正式[2 + 2 + 1]反应,用于五和三取代吡咯的氧化合成:类似于经典的Pauson-Khand型环戊烯酮合成的亚硝基类似物。鉴于早期过渡金属氧化还原催化的稀缺性,提出了初步的机理研究。最初的化学计量和动力学研究表明,该反应的机理是通过正式的Ti II / Ti IV进行的氧化还原催化循环,其中由[2 + 2]炔烃+ Ti亚氨基偶合反应生成的氮杂环丁烷环丁烯中间体经历第二次炔烃插入,然后还原消除,得到吡咯和Ti II物质。催化转换的关键成分是通过η2-二氮杂苯-Ti II络合物的歧化将Ti II物种再氧化为Ti IV酰亚胺基。
Copper-Catalyzed Double N-Vinylation of Aromatic Amines: An Efficient Synthesis of Various Substituted N-Arylpyrroles
作者:Qian Liao、Liyun Zhang、Fei Wang、Shutao Li、Chanjuan Xi
DOI:10.1002/ejoc.201000665
日期:——
A simple and efficient approach to various substituted N-arylpyrroles has been developed. The method is based on the copper-catalyzed sequential inter- and intramolecular N-vinylation of aromatic amines. The reactions proceed to afford substituted N-arylpyrroles in good-to-excellent yields using CuI as the precatalyst, tBuONa as the base, and N 1 ,N 2 -dimethylethane-1,2-diamine (DMEDA) as the ligand
Titanium (IV) compounds and methods of forming heterocyclic compounds using same
申请人:REGENTS OF THE UNIVERSITY OF MINNESOTA
公开号:US10065976B2
公开(公告)日:2018-09-04
The present disclosure provides Titanium (IV) compounds and methods of making heterocyclic compounds such as pyrroles using Titanium (IV) compounds. In certain embodiments, the Titanium (IV) compound is present in catalytic amounts.