Mechanochemical Synthesis of Diarylethynes from Aryl Iodides and CaC2

Abstract

A mechanochemical synthesis of diarylethynes from aryl iodides and calcium carbide as acetylene source is reported. The reaction is catalyzed by a palladium catalyst in the presence of copper salt, base and ethanol as liquid assisting grinding (LAG) additive. Various aryl and heteroaryl iodides have been converted in up to excellent yields.

Calcium Carbide: From Elemental Carbon to Isotope‐Economic Synthesis of 13C2‐Labeled Heterocycles†

“…In previously reported procedures, an excess of calcium carbide was used to maximize the yield of target products relative to substrates: 2—12 equivalents of calcium carbide were used to reach high conversion of substrates. [ 63‐83 ] But, in the synthesis of 13 C 2 ‐labeled compounds it is really important to achieve the high levels of insertion of Ca 13 C 2 ‐derived acetylene in target molecules.…”

Calcium carbide residue – a promising hidden source of hydrogen

“…Calcium carbide, as a source of acetylene, is used in organic synthesis, [43][44][45][46][47][48][49][50] catalysis, 51,52 mechanochemical activation, 53,54 and many related applications. [55][56][57] In 2021, the production of calcium carbide amounted to more than 27 million tons, while more than 75% was used for the production of acetylene, 58 thereby approximately 23 million tons of CCR were produced.…”