Direct Access to Titanocene Imides via Bis(η5:η1-penta-fulvene)titanium Complexes and Primary Amines,Organometallics

当前位置： X-MOL 学术 › Organometallics › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Direct Access to Titanocene Imides via Bis(η5:η1-penta-fulvene)titanium Complexes and Primary Amines
Organometallics ( IF 2.5 ) Pub Date : 2018-06-21 , DOI: 10.1021/acs.organomet.8b00264
Manfred Manßen ₁ , Simon de Graaff ₁ , May-Franzis Meyer ₁ , Marc Schmidtmann ₁ , Rüdiger Beckhaus ₁

Affiliation

The formation of the titanocene imido complexes 2b, 4, and 5 via double N–H bond activations at ambient temperature of sterically demanding amines (2,6-diisopropylaniline, tert-butylamine) by the use of the bis(η⁵:η¹-adamantylidenepentafulvene)titanium complex (1) has been investigated. The titanium imido complex 2b exists in equilibrium with its corresponding titanium monoamide complex 2a. The equilibrium can be shifted to the side of the imide 2b by increasing the temperature. Starting from the equilibrium 2a/2b, or the titanium imido pyridine adduct 5, a broad range of [2 + 2] cycloaddition reactions are realized. In reactions with alkynes, the regioselective formation of the azacyclobutenes 6 and 7 are observed. By using carbodiimides, asymmetric (8 and 10a) and symmetric cycloaddition products (9 and 10b) are formed. In the reaction with isocyanates, dependent on the substitution pattern of the Ti═NR imido unit, the C═O or the C═N [2 + 2] cycloaddition occurs, resulting in the N,O-bound ureato(2-) complex 11 or the N,N-bound ureato(2-) complex 13. In the presence of isocyanates and nitriles, the equilibrium 2a/2b results in ring enlargement reactions to six-membered rings (12, 14) by insertion of a second equivalent of the substrate into the Ti–N bonds.

中文翻译：

通过双直接访问茂钛酰亚胺（η ⁵：η ¹ -戊富烯）合钛配合物的胺和伯胺

作为二茂钛酰亚胺复合物的形成2b中，4和5通过双重N-H键的激活在空间要求的胺（2,6-二异丙基苯胺，环境温度叔丁基胺）通过使用双（η ⁵：η ¹已经研究了-金刚烷亚戊基富钛）钛配合物（1）。钛亚氨基络合物2b与其对应的钛单酰胺络合物2a平衡存在。通过升高温度，平衡可以转移到酰亚胺2b侧。从平衡2a / 2b开始，或者钛亚氨基吡啶吡啶加合物5，实现了大范围的[2 + 2]环加成反应。在与炔烃的反应中，观察到氮杂环丁烯6和7的区域选择性形成。通过使用碳二亚胺，形成不对称的（8和10a）和对称的环加成产物（9和10b）。在与异氰酸酯的反应中，取决于Ti═NR酰亚胺基单元的取代方式，会发生C═O或C═N[2 + 2]环加成反应，从而导致N，O键合的脲基（2-）络合物11或N，N束缚尿素（2-）复合物13。在异氰酸酯和腈，平衡的存在图2a / 2b中的结果在扩环反应的六元环（12，14由衬底入Ti-N键的第二当量的插入）。

更新日期：2018-11-29

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11