Ligand Tuning in Pyridine-Alkoxide Ligated Cp*Ir<sup>III</sup> Oxidation Catalysts
作者:Emma V. Sackville、Gabriele Kociok-Köhn、Ulrich Hintermair
DOI:10.1021/acs.organomet.7b00492
日期:2017.9.25
these precursors to catalytic C–H oxidation of ethyl benzenesulfonate with aqueous sodium periodate showed that the ligand substitution pattern, solution pH, and solvent all have pronounced influences on initial rates and final conversion values. Correlation with O2 evolution profiles during C–H oxidation catalysis showed these competing reactions to occur sequentially, and demonstrates how it is possible
吡啶醇盐连接的六种新型衍生物Cp * Ir III配合物(均质水和CH-H氧化催化剂的有效前体)已经合成,表征并通过光谱和动力学分析了配体效应。发现醇盐和吡啶取代基的变化会影响它们的溶液形态,活化行为和氧化动力学。这些前体在高碘酸钠水溶液催化CH-H氧化苯磺酸乙酯中的应用表明,配体的取代方式,溶液的pH值和溶剂都对初始速率和最终转化率有显着影响。与O 2相关 在C–H氧化催化过程中的演化曲线表明,这些竞争反应是相继发生的,并证明了如何通过N ^ O配体结构调节活性物种的活性和选择性。
Aggregative activation in heterocyclic chemistry. Part 5.† Lithiation of pyridine and quinoline with the complex base BuLi·Me2N(CH2)2OLi (BuLi·LiDMAE)
作者:Philippe Gros、Yves Fort、Paul Caubère
DOI:10.1039/a705027e
日期:——
It is shown that the complex base BuLi·LiDMAE reacts with pyridine to give metallated species which, after trapping by electrophiles, lead to 2-substituted pyridines in good to excellent yields. The same reactions have been less successfully performed with quinoline.
Electrochemical and Kinetic Insights into Molecular Water Oxidation Catalysts Derived from Cp*Ir(pyridine‐alkoxide) Complexes
作者:Emma V. Sackville、Frank Marken、Ulrich Hintermair
DOI:10.1002/cctc.201800916
日期:2018.10.9
ammonium nitrate (CAN) in water and aqueous tBuOH solution. Mechanisticstudies including H/D kinetic isotope effects and reaction progress kinetic analysis (RPKA) of oxygen evolution point to a dimer‐monomer equilibrium of the IrIV resting state preceding a proton‐coupled electron transfer (PCET) in the turnover‐limiting step (TLS). Finally, true electrochemically driven water oxidation is demonstrated
Transition-Metal Free Chemoselective Hydroxylation and Hydroxylation–Deuteration of Heterobenzylic Methylenes
作者:Yonghai Liu、Yang Yu、Chengyu Sun、Yiwei Fu、Zhiguo Mang、Lei Shi、Hao Li
DOI:10.1021/acs.orglett.0c03108
日期:2020.10.16
We developed an approach for direct selective hydroxylation of heterobenzylic methylenes to secondary alcohols avoiding overoxidation to ketones by using a KOBu-t/DMSO/air system. Most reactions could reach completion in several minutes to give hydroxylated products in 41-76% yields. Using DMSO-d6, this protocol resulted in difunctionalization of heterobenzylic methylenes to afford α-deuterated secondary alcohols (>93% incorporation). By employing this method, active pharmaceutical ingredients carbinoxamine and doxylamine were synthesized in two steps in moderate yields.
SOME POTASSIUM AMIDE-ACTIVATED PHENYLATIONS IN LIQUID AMMONIA (1)