Alkynes alcohols, palladium® chloride

Alkenes can be converted to succinic esters by reaction with carbon monoxide, an alcohol, and palladium chloride in the presence of mercuric chloride.1,12 The addition is mostly syn. In similar reaction, both terminal and internal alkynes can be converted to esters of maleic acid. 

Activated and deactivated positions in halopyridines exhibit marked difference in reactivity in palladium chemistry, whereas little difference in reactivity was observed among 2-, 4-, and 5-positions of halopyrimidines for their Sonogashira reactions [84]. While 2-iodo-4,6-dimethylpyrimidine was the most suitable substrate for preparing internal alkyne 176, the reaction of either the corresponding bromide or chloride was less efficient [85]. Good to excellent yields were obtained for the preparation of alkynylpyrimidines from most terminal alkynes with the exception of propargyl alcohols. Later reports showed that... 

A number of syntheses of di- and polyacetylenes has been reported. 1-Iodo-l-alkynes couple with terminal acetylenes under palladium-copper catalysis to give 1,3-diynes thus y-iodopropargyl alcohol and phenylacetylene afford compound 30. Oxidative coupling of 1 -alkynes to yield symmetrical 1,3-diynes is brought about by air and copper(I) chloride in the presence of N, A -tetramethylethylenediamine (equation Trialkylsilyl sub-... 

Aniline, acetanilide, benzyl alcohol or methyl benzoate containing a halogen atom in the or /zo-position react with 1 -alkynes in the presence of bis(triphenylphosphine)palladium(II) chloride and copper(I) iodide to give the corresponding o-alkynylbenzenes (e.g. equation 6). Some of the products can be cyclized the aniline derivative 53, for instance, is converted into 2-phenylindole in 99% yield on treatment with a catalytic amount of copper(I) iodide. ... 

As shown in the next scheme, palladium-catalyzed coupling of iodoaniline with bis-triethylsilyl protected butynol in the presence of Na2C03 provided a mixture of indoles. This mixture was desilylated with aqueous HCl in MeOH to furnish the tryptophol in two steps. Protection of the alkyne prevented coupling at the terminal carbon of the alkyne and triethylsilyl (TES) was found to be optimal because it offered the correct balance between reactivity (rate of coupling) and stability. Notably, this palladium-catalyzed process does not require the use of triphenyl phospine, tetrabutyl ammonium chloride, or lithium chloride. The alcohol was converted into the mesylate and then treated directly with 40% dimethylamine to afford rizatriptan, which was purified via recrystallization after forming the benzoate salt. 

The examples of oxidative carbonylations of alkynes were reported on in 1964. Here, Tsuji et al. described the palladium-mediated transformation of acetylene into muconyl chloride, fumaryl and maleic acid chloride (Scheme 8.15) [77]. Later on, they used diphenylacetylene as a substrate for the synthesis of lactones in the presence of alcohol and HCl [78, 79]. 

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