Trialkylammonium salt degradation: implications for methylation and cross-coupling
作者:Jack B. Washington、Michele Assante、Chunhui Yan、David McKinney、Vanessa Juba、Andrew G. Leach、Sharon E. Baillie、Marc Reid
DOI:10.1039/d1sc00757b
日期:——
being the key reactive species in applied methylation procedures. Furthermore, the effect of halide and non-nucleophilic counterions on salt degradation has been investigated, along with deuterium isotope and solvent effects. New mechanistic insights have enabled the investigation of the use of trimethylanilinium salts in O-methylation and in improved cross-coupling strategies. Finally, detailed computational
已知三烷基铵(最显着的是N,N,N-三甲基苯铵)盐通过芳基和N-甲基均显示出双重反应性。因此,这些盐已广泛应用于交叉偶联,芳基醚化,氟放射性标记,相转移催化,超分子识别,聚合物设计和(最近)甲基化。然而,它们作为亲电甲基化试剂的应用仍未得到充分开发,并且缺乏对它们的芳基化与甲基化反应性的了解。本研究提出了N,N,N的机械降解分析。-三甲基苯胺盐,并突出了这一重要类别盐对合成应用的意义。在固相和固溶阶段的动力学降解研究已经深入了解了影响苯胺盐稳定性的物理和化学参数。盐降解的1 H NMR动力学分析表明,热降解为甲基碘和母体苯胺,与闭壳S N一致2位降解途径,而甲基碘是应用甲基化程序中的关键反应物种。此外,还研究了卤化物和非亲核抗衡离子对盐降解的影响,以及氘同位素和溶剂的影响。新的力学见解使人们能够研究三甲基苯胺盐在O-甲基化中的应用以及在改进的交叉偶联策略中的应用。最后,详细的计算研究有助于
Nickel-Catalyzed Borylation of Aryl and Benzyl 2-Pyridyl Ethers: A Method for Converting a Robust <i>ortho</i>
-Directing Group
The nickel‐catalyzed borylation of aryl2‐pyridyl ethers via the loss of a 2‐pyridyloxy group is described. This method allows a 2‐pyridyloxy group to be used as a convertible directing group in C−H bond functionalization reactions. The nickel catalyst can also borylate arylmethyl 2‐pyridyl ethers, in which the stereochemistry at the benzylic position is retained in the case of chiral secondary benzylic