Alkyne metathesis introduction

Alkyne metathesis, using either preformed carbyne complexes, or carbyne complexes generated in situ, has started to find use in recent years, particularly as more reactive catalysts have been developed. The introduction of stable carbyne complexes, such as tungsten complex 8.483, as more-active catalysts started to make the reaction practicable for organic synthesis. ... 

Metal-alkylidene and alkylidyne complexes bonded to silica via silyloxy ligands are also well-defined active alkene and alkyne metathesis catalysts. Recall that Schrock had turned metathesis-inactive alkylidene complexes into active ones by the introduction of alkoxy ligands. In Basset s catalysts, this beneficial role is played by a silyloxy ligand from silica. 15.2,15.31a the catalysts [(SiO)M(=CH-r-Bu)... 

Initially alkynes were polymerised by trial and error with the use of Ziegler type recipes and the mechanism for these reactions may well be an insertion type mechanism. Undefined metathesis catalysts of ETM complexes were known to give poly-acetylene in their reaction with alkynes (acetylene) [45] and metallacycles were proposed as intermediates. Since the introduction of well-defined catalysts far better results have been obtained. The mechanism for this reaction is shown in Figure 16.24 [46], The conductive polymers obtained are soluble materials that can be treated and deposited as solutions on a surface. 

Introduction to Ring-Opening Metathesis Polymerization (ROMP) and 1-Alkyne Polymerization... 

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