Can the Ti(OiPr)<sub>4</sub>/<i>n</i>BuLi combination of reagents function as a catalyst for [2+2+2] alkyne cyclotrimerisation reactions?
作者:Gabriela Siemiaszko、Yvan Six
DOI:10.1039/c8nj04931a
日期:——
Catalysis of the cyclotrimerisation of alkynes with the Ti(OiPr)4/nBuLi system was studied, leading to the development of a particularly convenient and reliable protocol. This method allows the [2+2+2] cycloadditionreaction to proceed within a few minutes under microwave conditions, with generally good selectivity from a variety of aromatic and aliphatic alkynes.
研究了用Ti(OiPr)4 / n BuLi体系催化炔烃的环三聚反应,从而开发了一种特别方便和可靠的方案。该方法允许[2 + 2 + 2]环加成反应在微波条件下在几分钟之内进行,对各种芳族和脂族炔烃的选择性通常都很好。
Iron-catalyzed regioselective cyclotrimerization of alkynes to benzenes
作者:Suhas Shahaji Gawali、Chidambaram Gunanathan
DOI:10.1016/j.jorganchem.2018.12.007
日期:2019.2
catalyzed the regioselective [2+2+2] cyclotrimerization of terminal aryl and alkyl alkynes to provide the 1,2,4-trisubstituted benzene molecules. Interestingly, internal alkynes also exhibited similar cyclization and resulted in hexa-substituted benzene compounds. Increased steric bulk on pincer ligands diminished the selectivity for cycloaddition. Cyclotrimerization reactions proceeded at room temperature
Exploiting Guanidine as a Ligand in Cobalt-Catalyzed Alkyne Cyclotrimerizations
作者:James Stambuli、Chad Eichman、Jason Bragdon
DOI:10.1055/s-0030-1259931
日期:2011.5
The synthesis of polysubstituted arenes is accomplished via the regioselective cyclotrimerization of alkynes utilizing a guanidine-ligated cobalt catalyst.
carbyne complexes (≡SiO)xW(≡CH)(Me)y (x = 1, y = 2; x = 2, y = 1) toward alkynes is reported. We found that they are efficient precatalysts for terminalalkyne cyclotrimerization with high TONs. We also demonstrate that this catalyst species is active for alkyne cyclotrimerization without the formation of significant alkynemetathesis products. Additional DFT calculations highlight the importance of the
Ti(OiPr)4/nBuLi: an attractive reagent system for [2+2+2] cyclotrimerisation reactions
作者:V. A. Rassadin、E. Nicolas、Y. Six
DOI:10.1039/c4cc02698e
日期:——
A convenient method for the [2+2+2] cyclotrimerisation of alkynes using Ti(OiPr)4/nBuLi is presented. Homotrimerisation of arylacetylenes proceeds within minutes with excellent regioselectivity. Moreover, the intermolecular construction of ABB heterotrimers can be achieved selectively from two different alkynes with similar electronic properties. The method is also suitable for the synthesis of pyridines.