Acyl halides with organometallic

Palladium-catalyzed cross-coupling of acyl halides with organometallic reagents of zinc and tin is a convenient synthetic route to ketones and aldehydes. Typical examples are shown in eq (85) and (86) [116,117]. 

Pd-catalyzed coupling of acyl halides with organometallic reagents is a useful synthetic method of ketones. The alkylzinc reagent 127, prepared from the corresponding alkyl iodide with Zn/Cu couple, was coupled with the acid chloride 128 to give the ketone 129 in 50 % yield and used for the total synthesis of amphidinolide T14 [55]. 

Reaction of halo ketones or diazo ketones with boranes 0-102 Carbonylation of alkyl halides 0-104 Reaction between acyl halides and organometallic compounds 0-105 Reaction between other acid derivatives and organometallic compounds... 

Acyl halides react with organometallic reagents without catalysts, but sometimes the Pd-catalyzed reactions give higher yields and selectivity than the Lincatalyzed reactions. Acyl halides react with Pd(0) to form the acylpalladium complexes 846, which undergo facile transmetallation. 

The Conversion of Acyl Halides to Ketones With Organometallic Compounds ... 

Organopalladium intermediates are also involved in the synthesis of ketones and other carbonyl compounds. These reactions involve acylpalladium intermediates, which can be made from acyl halides or by reaction of an organopalladium species with carbon monoxide. A second organic group, usually arising from any organometallic reagent, can then form a ketone. Alternatively, the acylpalladium intermediate may react with nucleophilic solvents such as alcohols to form esters. 

II c., Cl 0 M L- X c Reaction of acyl halides or other acid derivatives with organometallic compounds... 

Organonitrogen-lithium compounds, and particularly lithium amides (R2NLi), are widely used both in organic and in organometallic syntheses. For the former, these strong bases are employed as proton abstractors (5-8), to generate new organolithiums. These can then be derivatized with so-called electrophiles, e.g., alkyl and acyl halides (E+ = R+ and R—C+=0) and trimethylsilylchloride (E+ = MeaSi+) [Eq. (1)]. 

OTHER ORGANOMETALLIC REAGENTS (see also Carbonylation, Fluorination, Reformatsky reaction) with acids and acyl derivatives with acid halides Benzylchlorobis(triphenyl-phosphine)palladium(II), 30 Cadmium, 60... 

OTHER ORGANOMETALLIC REAGENTS, with acids and acyl derivatives, with acid halides (Continued)... 

Alkynyllithium reagents cleave the S—S bond of [Fe2(CO)6(/t-S)2] to give 524, which can undergo intramolecular addition of sulfur to the a (525) or P (526) carbon atom of the acetylenic group when treated with electrophiles (Q ) like H+, aldehydes, and group 4 organometallic halides. With alkyl halides and acetyl chloride, only S-alkylation or S-acylation is observed (292,293). 

The mechanism of palladium-catalyzed coupling of organic halides with tetrasubstituted organotins has been widely studied by Stille and a general understanding of the mechanism is critical to further developments in this area. The use of other organometallics in palladium-catalyzed acylation will follow this discussion, as well as further examples where this method has been used. 

Many other types of organometallics which are not acylated directly acid chlorides and which do not undergo addition to ketones may still transmetallate into the acylpalladiumfll) complex. Simple alkyl organomercurials have been acylated in this fashion to give moderate to good yields of ketones. " Larock has studied the palladium-catalyzed acylation of vinylmercury(II) compounds with acyl halides (equation 104). The reaction was only modestly productive and could not compare to the yield provided by aluminum chloride catalysis. 

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