Mesoionic carbenes (MICs), derived from alkylation and deprotonation of triazoles, are shown to form stable complexes with BH3. The synthesis of triazoles via Huigsen cycloadditions provides considerable structural diversity. Several routes to MIC-boranes are described, and their structures have been characterized by X-ray crystallography. As predicted on the basis of the increased sigma-donor capacity of MICs by comparison to NHCs, the MIC-borane adducts are more reactive reducing agents.
Copper(II) triflate doubly catalyzed the substitution of benzylic acetates by TMSN3 and the subsequent 1,3-dipolar addition with an alkyne in one pot. This procedure afforded the preparation of 1,4-disubstituted 1,2,3-triazoles in good yields starting from the easily accessible acetates without isolating an organic azide using a single catalyst.
作者:Changwei Shao、Xinyan Wang、Jimin Xu、Jichen Zhao、Qun Zhang、Yuefei Hu
DOI:10.1021/jo101495k
日期:2010.10.15
presence of carboxylic acids and the latter two steps can be promoted significantly by carboxylic acids. Benzoic acid showed the best promotion activity, and the acids with strong chelating ability to Cu(I) ion could not serve for this purpose. Thus, the first carboxylic acid-promoted highly efficient CuAAC was established.
作者:Changwei Shao、Xinyan Wang、Qun Zhang、Sheng Luo、Jichen Zhao、Yuefei Hu
DOI:10.1021/jo200869a
日期:2011.8.19
In this novel acid–base jointly promoted CuAAC, the combination of CuI/DIPEA/HOAc was developed as a highly efficient catalytic system. The functions of DIPEA and HOAc have been assigned, and HOAc was recognized to accelerate the conversions of the C–Cu bond-containing intermediates and buffer the basicity of DIPEA. As a result, all drawbacks occurring in the popular catalytic system CuI/NR3 were overcome
在这种新型的酸碱共同促进的CuAAC中,CuI / DIPEA / HOAc的结合被开发为一种高效的催化体系。已经指定了DIPEA和HOAc的功能,HOAc被认为可以加速含C–Cu键的中间体的转化并缓冲DIPEA的碱性。结果,容易克服了流行的催化体系CuI / NR 3中发生的所有缺点。
Ruthenium-Catalyzed Alkenylation of Arenes with Alkynes or Alkenes by 1,2,3-Triazole-Directed C-H Activation
作者:Xing Guang Li、Kai Liu、Gang Zou、Pei Nian Liu
DOI:10.1002/ejoc.201402938
日期:2014.12
The ruthenium-catalyzedalkenylation of arenes with alkynes or alkenes has been achieved by using 1,2,3-triazole as the directing group for the C–Hactivation. With [Ru(p-cymene)Cl2]2 as the catalyst and Cu(OAc)2·H2O and AgSbF6 as additives, various triazole-substituted arenes reacted readily with a range of internal alkynes or terminal alkenes to afford di- or monoalkenylated arenes with high regioselectivity
Highly efficient click reaction on water catalyzed by a ruthenium complex
作者:Hai Xiao Siyang、Hui Ling Liu、Xin Yan Wu、Pei Nian Liu
DOI:10.1039/c4ra12960a
日期:——
The highlyefficient click reaction between terminal alkynes and azides has been achieved on water using rutheniumcomplex RuH2(CO)(PPh3)3 as the catalyst, and the catalyst loading was decreased to 0.2 mol% on water from 5 mol% in organic solvent. The RuH2(CO)(PPh3)3/H2O system also catalyzed the one-pot click reaction of bromides, sodium azide and alkynes; in this process, azides formed in situ and