Copper‐Containing Mineral Mediated Glaser Coupling of Terminal Alkynes

Abstract

Copper is one of the most abundant metals on the Earth. Elemental copper, as well as its alloys and compounds are widely used as catalysts in organic chemistry. By utilizing naturally occurring ores, the non-eco-friendly copper smelting process can be bypassed, leading to green and environmentally friendly procedures in comparison to the use of synthetic copper compounds. In this study we wish to present a more economical method for the production of symmetric diynes starting from various terminal acetylenes in a Glaser-Hay reaction. Out of the seven tested naturally occurring coppercontaining minerals, chalcocite (Cu 2 S) and bornite (Cu 5 FeS 4 ) were the best applicable ones. These minerals were able to produce diynes in yields comparable to those obtained with their synthetic analogues, furthermore they proved to be partly reusable.

A Simple and Practical Bis-N-Heterocyclic Carbene as an Efficient Ligand in Cu-Catalyzed Glaser Reaction

“…However, it usually needs a stoichiometric amount of copper salts, excess oxidants, rigid inorganic bases, and high temperature to afford low to moderate yields for aliphatic diynes. On the other hand, Glaser coupling of terminal alkynes catalyzed using copper-containing heterogeneous catalyst has also reported in very recently [ 44 , 45 ]. Despite the great progress, to the best of our knowledge, few catalyst systems have been reported for the homocoupling of terminal alkynes under a neutral condition with a mild condition [ 46 ].…”

CCl4-TMEDA-CuCl—A Novel Convenient Catalytic System for Dimerization of Terminal Acetylenes in Mild Conditions

“…Heterogeneous catalysis has also been used for this aim. For example, copper hydroxide on TiO 2 [54], cuprous chloride-doped zeolites [55][56][57], silica-supported Cu(II)-hydrazone coordination compounds [58], Cu 3 (BTC) 2 metal organic framework [59] and even naturally occurring copper-containing minerals, chalcocite (Cu 2 S) and bornite (Cu 5 FeS 4 ) [60], have demonstrated high efficiency as catalysts for terminal alkyne coupling. The reaction was also performed in supercritical fluids [61,62], water [63,64], ionic liquids [65,66] and solvent-free conditions [67,68] and under photocatalysis [69].…”