Competition between π-Arene and Lone-Pair Halogen Coordination of Silylium Ions?
摘要:
In 2,6-diarylphenylSiR(2) cations, the 2,6-diarylphenyl (m-terphenyl) scaffold blocks incoming nucleophiles and stabilizes the positive charge at silicon by lateral ring interactions. Direct ortho-halogen and pi-electron-rich face coordination to silicon has been seen. For a series of cations bearing 2,6-difluoro-2',6'-dimethyl-X(n)-substituted rings, the relative contribution of these two modes of stabilization has been assessed. Direct coordination from an aryl fluoride is found to be comparable to that from the mesityl pi-face.
Gold-Catalyzed Hydroamination of Alkynes and Allenes with Parent Hydrazine
作者:Rei Kinjo、Bruno Donnadieu、Guy Bertrand
DOI:10.1002/anie.201100740
日期:2011.6.6
A diverse array of nitrogen‐containing compounds were formed by the addition of hydrazine to alkynes, diynes, enynes, and allenes in the presence of cationic gold(I) complexes with a cyclic (alkyl)(amino)carbene ligand (see scheme; the X‐ray crystal structure of the gold–hydrazine complex is shown). This hydroamination is an ideal initial step for the preparation of acyclic and heterocyclic bulk chemicals
[EN] NOVEL TRANSITION METAL COMPLEXES, THEIR PREPARATION AND USE<br/>[FR] NOUVEAUX COMPLEXES DE MÉTAUX DE TRANSITION, LEUR PRÉPARATION ET UTILISATION
申请人:LANXESS DEUTSCHLAND GMBH
公开号:WO2014187973A1
公开(公告)日:2014-11-27
Novel transition metal complexes are provided which represent viable catalysts for a broad variety of reactions such as hydrogenation reactions and metathesis reactions. Novel preparation processes are made available via unprecedented routes inter alia not involving structures according to Grubbs I or Grubbs II catalysts.
heterolytic activation of the Si–H bond. The molecular structure of a new example of such an adduct was resolved by X-ray diffraction analysis. Theoretical considerations support a donor–acceptor [C,N}Cp*IrIII-H]→[SiEt3]+ (C,N} = benzo[h]quinolinyl) formulation where the cationic silyl moiety acting as a Z ligand binds both Ir and H centers. Under the conditions of the catalysis, the latter adduct is assumed
合成了含有(五甲基环戊二烯基)铱(III)单元的一组iridacycles [C,N} Cp * Ir III -Cl](C,N} =苯并[ h ]喹啉,二苯并[ f,h ]喹啉)并衍生为与BArF型阴离子缔合的阳离子[C,N} Cp * Ir-NCMe] +。后者的盐因其在H 2中对HSiEt 3的潜在催化性能而进行了基准测试-释放测试反应。表现最佳的BArF型盐显示出能够以低的催化负载量(大约)促进反应的能力。乙腈,丙腈和一系列芳腈底物的自动串联氢化硅烷化为0.5–1 mol%。机理研究证实,Si-H键的亲电和杂合活化可初步形成硅烷-铱环加合物。通过X射线衍射分析解析了这种加合物的新实例的分子结构。理论上的考虑支持了施主-受主[C,N} Cp * Ir III -H]→[SiEt 3 ] +(C,N} =苯并[ h ]喹啉基)的配方,其中阳离子甲硅烷基部分充当Z配体结合Ir和
Enantioselective Synthesis of (+)-Estrone Exploiting a Hydrogen Bond-Promoted Diels−Alder Reaction
作者:Marko Weimar、Gerd Dürner、Jan W. Bats、Michael W. Göbel
DOI:10.1021/jo100053j
日期:2010.4.16
Starting from Dane’s diene and methylcyclopentenedione, (+)-estrone is synthesized along the Quinkert−Dane route in 24% total yield. The keystep is an enantioselective Diels−Alderreaction promoted by an amidiniumcatalyst as efficiently as by a traditional Ti-TADDOLate Lewis acid.
从 Dane 的二烯和甲基环戊烯二酮开始,沿 Quinkert-Dane 路线合成 (+)-雌酮,总产率为 24%。关键步骤是由脒催化剂与传统的 Ti-TADDOLate Lewis 酸一样有效地促进对映选择性 Diels-Alder 反应。
Alkali Metal Adducts of an Iron(0) Complex and Their Synergistic FLP-Type Activation of Aliphatic C–X Bonds
作者:Hendrik Tinnermann、Simon Sung、Dániel Csókás、Zhi Hao Toh、Craig Fraser、Rowan D. Young
DOI:10.1021/jacs.1c04815
日期:2021.7.21
coordinating [BArF20] anions, [1·M][BArF20] (M = Li, Na). The adducts are found to synergistically activate aliphatic C–X bonds (X = F, Cl, Br, I, OMs, OTf), leading to the formation of iron(II) organyl compounds of the type [FeR(CO)3(PMe3)2][BArF20], of which several were isolated and fully characterized. Stoichiometric reactions with the resulting iron(II) organyl compounds show that this system can be
我们报告了 Li +和 Na +阳离子与中性铁 (0) 络合物 [Fe(CO) 3 (PMe 3 ) 2 ] ( 1 )之间弱加合物的形成和完整表征,由弱配位 [BAr F 20 ] 阴离子,[ 1 ·M][BAr F 20 ] (M = Li, Na)。发现加合物协同激活脂肪族 C-X 键(X = F、Cl、Br、I、OMs、OTf),导致形成 [FeR(CO) 3 (PMe ) 类型的铁 (II)有机化合物3 ) 2 ][BAr F 20],其中几个被分离出来并完全表征。与所得铁(II)有机基化合物的化学计量反应表明,该系统可用于均偶联和交叉偶联反应以及新 C-E 键(E = C、H、O、N、S)的形成。此外,我们在温和条件下利用 [ 1 ·M] [BAr F 20 ] 作为催化剂在简单的加氢脱卤反应中展示其在催化反应中的潜在用途。最后,使用 DFT 和动力学实验探讨了活化机制,表明碱金属和铁(0)中心通过与分子内