Cleavage of alkynes

Thomsoni. Ov Click Organic Interactiveto use a web-based palette to predict products for the oxidative cleavage of alkynes. 

Oxidative cleavage of alkynes by a variety of reagents has been reviewed [35, 60, 70, 71]. In most cases the CC bond is broken, but in some cases a-diketones are formed instead of, or in addition to, carboxylic acids. Examples of both types of reaction are given in Tables 3.3 and 3.6. 

As with alkene cleavage the main reagent for alkyne oxidations is RuO. Oxidative cleavage of alkynes by a variety of reagents has been reviewed [4, 6, 12, 14, 15], The first oxidation of alkynes was noted by Pappo and Becker in 1956 they showed that l,2-fc/x(l-acetoxycyclohexyl)ethyne (2) (Fig. 1.5) gave the diketone. Minimal experimental details were given [195],... 

Protonolysis of alkenylboranes by carboxylic acids occurs readily. The stereochemistry of the alkenyl group is retained during the reaction and so hydroboration/protolytic cleavage of alkynes leads to cis alkenes. Deuterated... 

Oxidative cleavage of alkynes.1 This reagent (3 equiv.) cleaves 1-alkynes to the norcarboxylic acids in 55-80% yield. 

Predict the products of additions, oxidations, reductions, and cleavages of alkynes, including the orientation of the reaction (regiochemistry) and the stereochemistry. 

Carbyne ligands may bridge two (p) or three (p3) metal centres, providing a total of 3VE to the overall electron count. Earlier synthetic routes to such complexes involved the reactions of carbonyl metallates with 1,1,1-trihaloalkanes, or the cleavage of alkyne ligands coordinated to clusters (Figure 5.46). 

Cleavage of alkynes is generally rather difficult, but treatment of internal alkynes with an excess of Oxone with a ruthenium catalyst leads to aliphatic carboxylic acids... 

Reagent for mild oxidative cleavage of alkynes and carbonyl compds. Cryst. by subl. Mp 119-120°. 

Scheme 24 (a) Application of C-C triple bond cleavage of alkyne 145 to the ring-opening polymerization of 145 to produce polykettaie 146. (b) Mechanism fw this process... 

Scheme 25 Application of C-C triple bond cleavage of alkyne 152 to the functionalization of...

Cha KM, Jo EA, Jun CH (2009) Tandem catalytic triple-bond cleavage of alkyne in association with aldehyde, alkene, and water. Synlett 2939... 

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