Cp2Ti(II) Mediated Rearrangement of Cyclopropyl Imines.
Cp2Ti(II) Mediated Rearrangement of Cyclopropyl Imines.
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DOI：
10.1021/acs.organomet.3c00032
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发表时间：
2023-03
期刊：
影响因子：
2.8
通讯作者：
Jaekwan Kim;Dominic T. Egger;C. Frye;Evan P. Beaumier;Ian A. Tonks
中科院分区：
文献类型：
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作者：
Jaekwan Kim;Dominic T. Egger;C. Frye;Evan P. Beaumier;Ian A. Tonks
钛催化氧化炔与烯烃和偶氮化合物的碳胺化反应可以通过一个常见的氮杂环己烯中间体生成α，β-不饱和亚胺或环丙基亚胺。本文报道了通过环丙基亚胺与Cp_2Ti（BTMSA）（BTMSA =双（三甲基硅基）乙炔）开环合成模型氮杂钛并环己烯配合物（3）。3容易经历热或还原催化的环收缩成氮杂环戊烯（4），类似于在催化反应中形成α，β-不饱和亚胺的建议机制。分别通过用偶氮苯氧化3或4可以释放环丙基亚胺或α，β-不饱和亚胺，进一步暗示这些金属环在钛催化的碳胺化反应中的作用。
Ti-catalyzed oxidative alkyne carboamination with alkenes and azo compounds can yield either α,β-unsaturated imines or cyclopropyl imines through a common azatitanacyclohexene intermediate. Herein, we report the synthesis of a model azatitanacyclohexene complex (3) through the ring-opening of a cyclopropyl imine with Cp2Ti(BTMSA) (BTMSA = bis(trimethylsilyl)acetylene). 3 readily undergoes thermal or reductant-catalyzed ring contraction to an azatitanacyclopentene (4), analogous to the proposed mechanism for forming α,β-unsaturated imines in the catalytic reaction. A cyclopropyl imine or an α,β-unsaturated imine could be liberated via the oxidation of 3 or 4 with azobenzene, respectively, further implicating the role of these metallacycles in the Ti-catalyzed carboamination reaction.