Palladium compounds from Grignard reagents

Many transition metal alkyls react with carbon monoxide to give acyl compounds. In all these cases the acyl derivatives can be detected at least by infrared methods and in most cases isolated. Molybdenum, manganese, rhenium, iron, cobalt, rhodium, nickel, palladium, and platinum alkyls, Grignard reagents, and boranes, all react with carbon monoxide, and one can explain the products from these on the basis of carbon monoxide inserting into the metal alkyl. 

The most conspicuous property of aliphatic amines, apart from their fishy smell, is their high basicity, which usually precludes N-alkylations under acidic reaction conditions (last reaction, Scheme 6.3). Hence, alkylation of amines with tertiary alkyl groups is not usually possible without the use of highly stabilized carbocations which can be formed under basic reaction conditions. Rare exceptions are N-alkyla-tions of amines via radicals (Scheme 4.2), copper-catalyzed propargylations (Scheme 6.3), and the addition of amines to some Michael acceptors and allyl palladium or iridium complexes. Better strategies for the preparation of tert-alkylamines include the addition of Grignard reagents to ketone-derived imines [13] or the reduction of tert-alkyl nitro compounds. 

Vinyl halides react with alkyllithiums with the aid of a palladium(O) complex to give olefins stereospecifically in good yields. When Grignard reagents are employed instead of alkyllithium compounds, these reactions can be carried out catalytically with the palladium complex (Yamamura et al., 1975). or/Ao-Alkylated thiobenzophenones can be similarly prepared from 5-donor ligand or/Ao-metalated complexes (H. Alper and J. Kamenof, unpublished results). 

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