Hydroamination and Hydroalkoxylation Catalyzed by Triflic Acid. Parallels to Reactions Initiated with Metal Triflates
摘要:
Intermolecular additions of the O-H bonds of phenols and alcohols and the N-H bonds of sulfonamides and benzamide to olefins catalyzed by 1 mol % of triflic acid and studies to define the relationship between these reactions and those catalyzed by metal triflates are reported. Cyclization of an alcohol containing pendant monosubstituted and trisubstituted olefins catalyzed by either triflic acid or metal triflates form products from addition to the more substituted olefin, and additions of tosylamide catalyzed by triflic acid or metal triflates form indistinguishable ratios of the two N-alkyl sulfonamides.
Efficient Intramolecular Hydroalkoxylation/Cyclization of Unactivated Alkenols Mediated by Lanthanide Triflate Ionic Liquids
作者:Alma Dzudza、Tobin J. Marks
DOI:10.1021/ol8029559
日期:2009.4.2
Lanthanide triflates, Ln(OTf)3, serve as efficient catalysts for the intramolecular hydroalkoxylation (HO)/cyclization of primary/secondary and aliphatic/aromatic hydroxyalkenes in room temperature ionic liquids (RTILs). Cyclizations are effective in the formation of five- and six-membered oxygen heterocycles with Markovnikov-type selectivity. Reaction rates exhibit first-order dependence on [Ln3+]
作者:Saswata Gupta、Siyuan Su、Yu Zhang、Peng Liu、Donald J. Wink、Daesung Lee
DOI:10.1021/jacs.1c02237
日期:2021.5.19
demonstrated them as an aromatic equivalent of the Grubbs-type ruthenium alkylidene catalysts. These ruthenabenzenes can be prepared via an enyne metathesis and metallotropic [1,3]-shift cascade process to form alkyne-chelated ruthenium alkylidene intermediates followed by spontaneous cycloaromatization. The aromatic nature of these complexes was confirmed by spectroscopic and X-ray crystallographic data
金属芳烃构成了一类独特的芳族化合物,其中一种或多种过渡金属元素结合到芳族体系中,其母体是金属苯。与碳原型相比,金属苯的主要关注点之一通常涉及与其相对芳香性相关的结构特征。含过渡金属的金属苯也涉及某些催化过程,例如炔烃复分解聚合;然而,这些基于过渡金属的金属芳族化合物尚未开发为催化剂。在此,我们描述了一种生成多种钌苯的有效策略,并将它们证明为 Grubbs 型钌亚烷基催化剂的芳族等价物。这些钌苯可以通过烯炔复分解和金属化[1,3]-移位级联工艺制备,形成炔烃螯合的亚烷基钌中间体,然后自发环芳构化。这些配合物的芳香性质通过光谱和 X 射线晶体学数据得到证实,并通过 DFT 计算研究了环芳构化过程的机理途径。这些钌苯对复分解和其他转化表现出强大的催化活性,这说明金属苯不仅是具有结构和理论意义的化合物,而且还是开发新催化剂的新平台。这些配合物的芳香性质通过光谱和 X 射线晶体学数据得到证实,并通过
Efficient Intramolecular Hydroalkoxylation of Unactivated Alkenols Mediated by Recyclable Lanthanide Triflate Ionic Liquids: Scope and Mechanism
作者:Alma Dzudza、Tobin J. Marks
DOI:10.1002/chem.200902269
日期:2010.3.15
catalytic pathway that involves kinetically significant intramolecular proton transfer. The present activation parameters—enthalpy (ΔH≠)=18.2 (9) kcal mol−1, entropy (ΔS≠)=−17.0 (1.4) eu, and energy (Ea)=18.2 (8) kcal mol−1—suggest a highly organized transition state. Proton scavenging and coordinative probing results suggest that the lanthanide triflates are not simply precursors of free triflic acid. Based
[Ln(OTf)3 ]类型的镧系三氟甲磺酸盐配合物(Ln = La,Sm,Nd,Yb,Lu)可作为有效的可循环催化剂,用于伯/仲和脂族/芳族化合物的快速分子内加氢烷氧基化(HO)/环化咪唑基室温离子液体(RTIL)中的羟基烯烃,生成相应的呋喃,吡喃,螺双环呋喃,螺双环呋喃/吡喃,苯并呋喃和异色满衍生物。产物直接从催化溶液中分离出来,转化表现出马尔可夫尼科夫区域选择性,周转频率高达47 h -1在120°C下。初级烯醇环化的环大小速率依赖性为5> 6,与空间控制的过渡态一致。末端烯醇的加氢烷氧基化/环化速率比内部烯醇的加氢烷氧基化/环化速率稍快,这表明在环状过渡态中适度的空间需求。芳基官能化羟基烯烃的环化速率比线性烯醇的环化速率更快,而五元和五元/六元螺双环骨架也被区域选择性封闭。在主要的空间受限的烯醇的环化过程中,从La 3+(1.160Å)到Lu 3+,对金属离子半径的周转频率依赖性降低了约80倍(0
Hydroamination and Hydroalkoxylation Catalyzed by Triflic Acid. Parallels to Reactions Initiated with Metal Triflates
作者:Devon C. Rosenfeld、Shashank Shekhar、Akihiro Takemiya、Masaru Utsunomiya、John F. Hartwig
DOI:10.1021/ol061174+
日期:2006.9.1
Intermolecular additions of the O-H bonds of phenols and alcohols and the N-H bonds of sulfonamides and benzamide to olefins catalyzed by 1 mol % of triflic acid and studies to define the relationship between these reactions and those catalyzed by metal triflates are reported. Cyclization of an alcohol containing pendant monosubstituted and trisubstituted olefins catalyzed by either triflic acid or metal triflates form products from addition to the more substituted olefin, and additions of tosylamide catalyzed by triflic acid or metal triflates form indistinguishable ratios of the two N-alkyl sulfonamides.