Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton‐Coupled Electron Transfer
作者:Elaine Tsui、Anthony J. Metrano、Yuto Tsuchiya、Robert R. Knowles
DOI:10.1002/anie.202003959
日期:2020.7.13
We report a catalytic, light‐driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible‐light irradiation in the presence of an IrIII‐based photoredox catalyst, a Brønsted base catalyst, and a hydrogen‐atom transfer (HAT) co‐catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct
我们报告了一种催化光驱动方法,用于未活化烯醇的分子内加氢醚化以提供环醚产品。这些反应在 Ir III基光氧化还原催化剂、布朗斯台德碱催化剂和氢原子转移 (HAT) 助催化剂存在下在可见光照射下发生。反应性烷氧基被认为是关键中间体,是通过质子耦合电子转移机制直接均裂激活醇 O−H 键而产生的。该方法表现出广泛的底物范围和高官能团耐受性,并且适应多种烯烃取代模式。还提出了证明该催化系统扩展到碳醚化反应的结果。
<i>Z</i>-Selective Homodimerization of Terminal Olefins with a Ruthenium Metathesis Catalyst
作者:Benjamin K. Keitz、Koji Endo、Myles B. Herbert、Robert H. Grubbs
DOI:10.1021/ja203488e
日期:2011.6.29
The cross-metathesis of terminal olefins using a novel rutheniumcatalyst results in excellent selectivity for the Z-olefin homodimer. The reaction was found to tolerate a large number of functional groups, solvents, and temperatures while maintaining excellent Z-selectivity, even at high reaction conversions.
使用新型钌催化剂进行末端烯烃的交叉复分解,对 Z-烯烃均二聚体具有优异的选择性。研究发现,即使在高反应转化率下,该反应也能耐受大量官能团、溶剂和温度,同时保持优异的 Z 选择性。
Ru-based Z-selective metathesis catalysts with modified cyclometalated carbene ligands
作者:Sarah M. Bronner、Myles B. Herbert、Paresma R. Patel、Vanessa M. Marx、Robert H. Grubbs
DOI:10.1039/c4sc01541j
日期:——
A series of cyclometalated Z-selective ruthenium olefin metathesis catalysts with alterations to the N-heterocyclic carbene (NHC) ligand were prepared.
Cyclometalated <i>Z</i>-Selective Ruthenium Metathesis Catalysts with Modified N-Chelating Groups
作者:Myles B. Herbert、Benjamin A. Suslick、Peng Liu、Lufeng Zou、Peter K. Dornan、K. N. Houk、Robert H. Grubbs
DOI:10.1021/acs.organomet.5b00185
日期:2015.6.22
order to design improved rutheniumcatalysts for Z-selective olefinmetathesis reactions, four cyclometalated catalysts with new chelated architectures were synthesized, structurally characterized, and tested in metathesis assays. The mechanism of formation of each was explored using DFT calculations. Of note, two complexes are derived from activation of a tertiary C–H bond, and one features a four-membered
A ruthenium catalyst for Z-selective olefin metathesis has been synthesized from a readily accessible N-heterocyclic carbene (NHC) ligand that is prepared using an efficient, practical, and scalable multicomponent synthesis. The desired ruthenium complex with cyclometalated NHCligand is obtained by means of selective C(sp3)-H activation at the adamantyl fragment and X-ray diffraction analysis unambiguously