Cyclotrimerization of terminal alkynes catalyzed by the system of NiCl2/Zn and (benzimidazolyl)-6-(1-(arylimino)ethyl)pyridines
作者:Chanjuan Xi、Zelin Sun、Yongbing Liu
DOI:10.1039/c3dt51674a
日期:——
An effective regioselective cyclotrimerization of terminal alkynes is achieved by the direct utilization of NiCl2·6H2O, Zn, and 2-(benzimidazolyl)-6-(1-(arylimino)ethyl)pyridine in one step under ambient temperature.
Iron-Catalyzed Trimerization of Terminal Alkynes Enabled by Pyrimidinediimine Ligands: A Regioselective Method for the Synthesis of 1,3,5-Substituted Arenes
作者:Julianna S. Doll、Robert Eichelmann、Leif E. Hertwig、Thilo Bender、Vincenz J. Kohler、Eckhard Bill、Hubert Wadepohl、Dragoş-Adrian Roşca
DOI:10.1021/acscatal.1c00978
日期:2021.5.7
to a functional-group-tolerant methodology for the catalytic trimerization of terminal aliphatic alkynes. Remarkably, in contrast to established alkyne trimerization protocols, the 1,3,5-substituted arenes are the main reaction products. Preliminary mechanistic investigations suggest that the enhanced π-acidity of the pyrimidine ring, combined with the hemilability of the imine groups coordinated to
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
A new [2+2+2] cycloaddition procedure relying on the use of an air-stable iron precatalyst is described, which allows the construction of aromatic and nitrogen-containing heteroaromatic rings in green solvents and mild conditions. Cycloadditions and cross-cycloadditions between 1,6- or 1,7-diynes and alkynes are reported, with a broad functional tolerance, leading to a variety of functionalizable scaffolds