Synthesis of Chromium(II) Complexes with Chelating Bis(alkoxide) Ligand and Their Reactions with Organoazides and Diazoalkanes
Synthesis of Chromium(II) Complexes with Chelating Bis(alkoxide) Ligand and Their Reactions with Organoazides and Diazoalkanes
复制标题
DOI：
10.3390/molecules25020273
复制
发表时间：
2020-01
期刊：
影响因子：
4.6
通讯作者：
Sudheer S. Kurup;R. Staples;Richard L. Lord;Stanislav Groysman
中科院分区：
文献类型：
--
作者：
Sudheer S. Kurup;R. Staples;Richard L. Lord;Stanislav Groysman
本文报道了一种新的铬（Ⅱ）与螯合双烷氧基配体[OO]Ph（H2[OO]Ph = [1，1 ′：4′，1 Mobi '-三联苯]-2，2 Mobi'-二基双（二苯基甲醇））配合物的合成及其在催化由叠氮化物和异氰化物制备N，N-二甲基酰亚胺中的反应性。得到两种不同的Cr（II）配合物，作为结晶溶剂的函数：单核Cr[OO]Ph（THF）2（在甲苯/THF中，THF =四氢呋喃）和双核Cr 2（[OO]Ph）2（在CH 2Cl 2/THF中）。用密度泛函理论计算了Cr[OO]Ph（THF）2的电子结构和成键。分离的Cr2（[OO]Ph）2与4-MeC 6 H4 N3、4-MeOC 6 H4 N3或3，5-Me 2C 6 H3 N3进行简单反应，产生抗磁性Cr（VI）双（亚氨基）配合物; Cr[OO]Ph（N（4-MeC 6 H4））2的结构通过X射线晶体学证实。Cr2（[OO]Ph）2与体积较大的叠氮化物N3 R（MesN 3，AdN 3）反应形成顺磁性产物，表示为Cr[OO]Ph（NR）。尝试形成C1-亚烷基络合物（使用N2 CPh 2）反而形成铬（VI）双（二苯基亚甲基肼基）络合物Cr[OO]Ph（NNCPh 2）2。研究了含不同芳基叠氮化合物和异腈化合物的叠氮/异腈混合物催化合成N-酰亚胺的反应。发现N-酰亚胺的形成取决于有机叠氮化物的性质：而大体积的mesylazide导致与所有异腈形成N-酰亚胺，对于3，5-二甲基苯基叠氮化物或4-甲基苯基叠氮化物没有观察到碳二亚胺的形成。用NO+处理Cr2（[OO]Ph）2或H2[OO]Ph导致形成[1，2-B]-二氢茚并芴，可能通过配体的碳阳离子介导的环化获得。
Synthesis of new chromium(II) complexes with chelating bis(alkoxide) ligand [OO]Ph (H2[OO]Ph = [1,1′:4′,1′’-terphenyl]-2,2′’-diylbis(diphenylmethanol)) and their subsequent reactivity in the context of catalytic production of carbodiimides from azides and isocyanides are described. Two different Cr(II) complexes are obtained, as a function of the crystallization solvent: mononuclear Cr[OO]Ph(THF)2 (in toluene/THF, THF = tetrahydrofuran) and dinuclear Cr2([OO]Ph)2 (in CH2Cl2/THF). The electronic structure and bonding in Cr[OO]Ph(THF)2 were probed by density functional theory calculations. Isolated Cr2([OO]Ph)2 undergoes facile reaction with 4-MeC6H4N3, 4-MeOC6H4N3, or 3,5-Me2C6H3N3 to yield diamagnetic Cr(VI) bis(imido) complexes; a structure of Cr[OO]Ph(N(4-MeC6H4))2 was confirmed by X-ray crystallography. The reaction of Cr2([OO]Ph)2 with bulkier azides N3R (MesN3, AdN3) forms paramagnetic products, formulated as Cr[OO]Ph(NR). The attempted formation of a Cr–alkylidene complex (using N2CPh2) instead forms chromium(VI) bis(diphenylmethylenehydrazido) complex Cr[OO]Ph(NNCPh2)2. Catalytic formation of carbodiimides was investigated for the azide/isocyanide mixtures containing various aryl azides and isocyanides. The formation of carbodiimides was found to depend on the nature of organoazide: whereas bulky mesitylazide led to the formation of carbodiimides with all isocyanides, no carbodiimide formation was observed for 3,5-dimethylphenylazide or 4-methylphenylazide. Treatment of Cr2([OO]Ph)2 or H2[OO]Ph with NO+ leads to the formation of [1,2-b]-dihydroindenofluorene, likely obtained via carbocation-mediated cyclization of the ligand.