Palladium-catalysed reactions telomerization

Palladium complexes generated from the sulfonated ligand 5 (Table 2 R=Me, n=0,l,2) were also used to catalyse the telomerization of 1,3-butadiene with water108 and from the aminophosphines 83 (Table 5 R=Ph R =H,Me R"=Me,iPr n=2,3) with MeOH to give l-methoxy-2,7-octadiene in selectivities up to 78% at conversions ranging from 52 to 80%.232 Pd/83 (R=Ph R =H,Me R"=Me,iPr n=2,3) catalysts are more active but less selective in the latter reaction compared to their tppts counterparts.232 9... 

Bessmertnykh A, Henin F, Muzart I (2005) Palladium-catalysed telomerization of butadiene with aldoses a convenient route to non-ionic surfactants based on controlled reactions. J Mol Catal A Chem 238 199-206... 

Telomerization of Isoprene.—Reviews have appeared on isoprene and chloro-prene, and on the complex reactions of isoprene to form terpenoids (in Japanese). Isoprene reacts with magnesium, especially in the presence of Lewis acids, and the resulting complex gives adducts with aldehydes. As usual in this type of reaction, a very complex mixture is obtained. The palladium-chloride-catalysed reaction of isoprene with acetic acid gives different products in different solvents. Monomers predominate in benzene [2-methylbut-2-enyl acetate (5) and 3-methylbut-2-enyl acetate (6)] while dimers [(7), (8), neryl (9), and geranyl (10) acetates] tend to be formed in tetrahydrofuran. Further details of the synthesis of Cio alcohols from isoprene and naphthyl-lithium are available, as well as of the in situ oxidation,but there is little of novelty (see Vol. 1, p. 17). 

Pd(acac)8+PPh3+Et8Al -catalysed telomerization of butadiene with HZ [Z=RS02 or R0(CH8) 0 ] yields the corresponding product (24). [Pd(PPh3)4] catalyses reaction (23) similar palladium-catalysed additions of... 

Some authors have proposed mechanisms based on bimetallic palladium species. Keim and colleagues, for instance, proposed a reaction mechanism for the telomerization of acetic acid with butadiene (Scheme 10), where the key intermediate is a bispalladium compound such as Pd2([i-1,2,3,6,7,8-r 6-octa-2,7-dien-l, 8-diyl)((j,-OAc)2] [65]. It was shown that these bimetallic compounds are able to catalyse telomerization in the presence of 1,3-butadiene, acetic acid and a phosphine ligand. 

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