Demidov Nikita, Grebogi Mateus, Bourne Connor, McKay Aidan P, Cordes David B, Stasch Andreas
EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK.
Molecules. 2023 Nov 13;28(22):7569. doi: 10.3390/molecules28227569.
This work reports the one-pot synthesis of sterically demanding aniline derivatives from aryllithium species utilising trimethylsilyl azide to introduce amine functionalities and conversions to new examples of a common '-chelating ligand system. The reaction of TripLi (Trip = 2,4,6-Pr-CH) with trimethylsilyl azide afforded the silyltriazene TripNN(SiMe) in situ, which readily reacts with methanol under dinitrogen elimination to the aniline TripNH in good yield. The reaction pathways and by-products of the system have been studied. The extension of this reaction to a much more sterically demanding terphenyl system suggested that TerLi (Ter = 2,6-Trip-CH) slowly reacted with trimethylsilyl azide to form a silyl(terphenyl)triazenide lithium complex in situ, predominantly underwent nitrogen loss to TerN(SiMe)Li in parallel, which afforded TerN(SiMe)H after workup, and can be deprotected under acidic conditions to form the aniline TerNH. TripNH was furthermore converted to the sterically demanding -diketimines nacnacH (=HC{RCN(Trip)}H), with R = Me, Et and Pr, in one-pot procedures from the corresponding 1,3-diketones. The bulkiest proligand was employed to synthesise the magnesium hydride complex [{(nacnac)MgH}], which shows a distorted dimeric structure caused by the substituents of the sterically demanding ligand moieties.
本工作报道了利用叠氮基三甲基硅烷引入胺官能团，从芳基锂物种一锅法合成空间位阻较大的苯胺衍生物，并将其转化为常见“螯合配体体系”的新实例。三异丙基苯基锂（TripLi，Trip = 2,4,6 - Pr₃C₆H₂）与叠氮基三甲基硅烷反应原位生成硅烷基三氮烯TripNN(SiMe₃)，其在消除氮气的情况下与甲醇反应，以良好的产率生成苯胺TripNH。对该体系的反应途径和副产物进行了研究。将此反应扩展到空间位阻更大的三联苯体系表明，三联苯锂（TerLi，Ter = 2,6 - Trip - C₆H₄）与叠氮基三甲基硅烷缓慢反应原位形成硅烷基（三联苯）三氮烯锂配合物，主要同时发生氮损失生成TerN(SiMe₃)Li，后处理后得到TerN(SiMe₃)H，并且在酸性条件下可以脱保护形成苯胺TerNH。此外，TripNH通过一锅法从相应的1,3 - 二酮转化为空间位阻较大的二酮亚胺nacnacH（=HC{RCN(Trip)}₂H），其中R = Me、Et和Pr。使用体积最大的前体配体合成氢化镁配合物[{(nacnac)MgH}]，其显示出由空间位阻较大的配体部分的取代基引起的扭曲二聚体结构。
