Carbonyls reaction with alkynes

An iron-catalyzed carbonylation reaction of alkynes 120 forming succinimides 121 by the aid of Fe(CO)5 78 or [Fe3(CO)i2] 119 has been reported by Beller et al. (Scheme 31) [94]. This reaction seems interesting as iron-carbonyl complexes are kinetically relatively inert. As a model system 3-hexyne was reacted with excess ammonia under 20 bar CO pressure. Employing a higher pressure leads to... 

Protonic acid and Lewis acids can activate carbonyls to facilitate the addition of nucleophile attacks in aqueous media. The Prins reaction, reaction with alkyne, and Friedel-Crafts-type reactions have been discussed in related chapters in detail. 

The reaction of iron-carbonyl complexes with alkynes led to cyclobutenediones, which is formally a [2 + 1 + 1]-cycloaddition process for the formation of a cyclobutene derivative (Scheme 9.22) [49]. Nevertheless, in this reaction the liberation of the ligand is initiated by addition of stoichiometric amounts of copper] 11) salts and the use of various alkynes leads to interesting products such as 30 in good yields. 

A study of the reactivity of the carbonyl-functional phospha-alkenes (305) has also been reported. The triphospha-Dewar-benzene (306) has been shown to undergo cycloaddition reactions with alkynes to form the triphosphabishomo-prismane system (307). Cycloaddition of t-butylphospha-ethyne to the phosphatriafulvene (308) results in the formation of a single isomer of the diphosphaisobenzene (309), having an allene system within the ring. This... 

The reactions of Ir-carbonyl complexes with alkynes require more drastic conditions e.g., -CpIr(CO)2 reacts slowly at high temperature (120-160°C) with CF3C=CCF3 to form cis and trans isomers of the cr-bridging alkyne complex, ( / -HCp)2lr2(CO)2(CF3C2CF3) Several mononuclear r/ -alkyneiridium complexes are known ... 

Alkylidene- and vinylcyclopropanes. The reagent effects cyclopropyl idenation of carbonyl compounds including esters and lactones. Reaction with alkynes gives vinylcyclopropanes on acidic workup. 

Reaction with alkynes 14, 11.2.3 Reaction with C2H4 14, 11.2.2 Reaction with metal carbonyls 14, 9.2.S.6 Reductive elimination of H2 from 14,... 

E3.25 Reactions of ruthenium carbonyl clusters with alkynes... 

It is well known that di- and tetrahydrofurans can be obtained by inter- and intramolecular 1,3-dipolar cycloaddition reactions of carbonyl ylides with alkynes and alkenes. This methodology has also been shown to be of value in the preparation of a furanophane <92TL57>. 

Highly substituted 4/f-pyrans are obtained from [4 + 2] cycloaddition reactions of a-ester-substituted a,P-imsaturated carbonyl compounds with alkynes promoted by a nickel(0) complex (14BCSJ1058) and by annulation reactions of a-allenals with chalcones mediated by the NHC catalyst 2 (Scheme 6) (140L4742). 

Additionally, the reactions with alkynes and iron catalyst were also applied to the carbonylative homocoupling of aryl iodides to give benzophenones [49]. As catalyst system, Fe(CO)5-Co2(CO)g was used under phase-transfer conditions to give carbonylate aryl iodides in moderate yields. 

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