Palladium catalysis Alkene amination

As stated above, aliphatic amines are potent ligands for electrophilic transition metals and are efficient catalyst poisons in attempted alkene animation reactions. However, tosylation of the basic amino group greatly reduces its complexing ability, yet does not compromise its ability to nucleophilically attack complexed alkenes. Thus, a variety of alkenic tosamides efficiently cyclized under palladium(II) catalysis producing N-tosylenamines in excellent yield (equations 17 and 18).32 Again, this alkene amination proceeded through an unstable a-alkylpalladium(II) species, which could be intercepted by carbon monoxide, to result in an overall aminocarbonylation of alkenes. With ureas of 3-hydroxy-4-pentenyl-amines (Scheme 7), this palladium-catalyzed process was quite efficient but it was somewhat less so with... 

Cyclic secondary amines are also produced by the ring expansion of O-sulphonyloximes via a Beckmann rearrangement/ the cyclization of a,aliphatic diamines by a ruthenium catalyst/ the palladium-promoted ring closure of amino-alkenes/ and the sulphonamidomercuration of 1,4- and 1,5-dienes. The latter two reactions form part of a wealth of new literature on the amination of olefins and acetylenes via aminomercuration " and via palladium catalysis. ... 

Selective C-H bond functionalization is one of the most important research topics in modem organic chemistry. For example, direct amination of alkenes through allylic Cjp -H functionalization has been well developed during the past decades [126-128]. Palladium catalysis was playing the leading role among these reactions. 

A final example of shape selective catalysis is the selective hydrogenation of alkynes, alkenes and other hydrocarbons over Pd complexes anchored to montmorillonite clay supports.29 In these studies, phosphines and amine ligands were first reacted with montmorillonite and then reacted with palladium (II) salts to form anchored Pd(II) complexes in the interlamellar spacings of the montmorillonite clay. 

Both [Pd(OAc)2] and [Pd(acac)2] were used as catalyst precursors, in the presence of PPhs or PBu"3. No catalysis occurred here in absence of the phosphorus ligand. When isoprene was carbonylated using [Pd(OAc)2] and PPhj as catalyst precursor, dimerization of the alkene did not take place, the ester of 4-methyl-3-pentenoic acid being formed as the only product. Because of its potential application to the synthesis of esters for lubricating oils, the dimerization-carbonylation of butadiene has received special attention. Basic phosphines such as PBu°3 and weakly basic tertiary amine solvents (quinoline, N,N-diethylaniline) were found to improve both the stability and activity of the catalyst system.In a further report in which PPr 3 was used as phosphorus ligand it was found that the addition of maleic anhydride caused a marked increase in the catalytic activity. It was believed that through coordination it stabilized the palladium(O) complexes formed against precipitation as metal. ... 

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