Telomerisation of Isoprene

Ueda and M. Matsui, Agric. and Biol. Ghent. (Japan), 1970, 34, 1115. 

Tanaka, T. Katagiri, and H. Okawa, Nippon Kagaku Zasshi, 1969, 90, 204 (Ghem. 

In the presence of lithium naphthalene in tetrahydrofuran, isoprene is dimerised to linear monoterpene homologues, and oxidation of the mixture by passage of oxygen gives 30—40% of Cio alcohols and 30% of C,o glycols. Of the mono-hydric alcohols, 10% nerol and 10% geraniol are obtained in addition to 5% of 

6-dimethylocta-l,7-dien-6-ol (69) and 55% 2,7-dimethylocta-2,6-dien-l-ol (70), with 20% unidentified product. The glycols are 50% each of 2,6- and 2,7-di-methylocta-2,6-diene-1,8-diol (71) and (72). Boration of the reaction mixture (boron trifluoride etherate) and hydrogen peroxide treatment of the organo-boranes leads to the same Cjo alcohols in slightly different proportions.  

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Gordillo A, Pachon LD, de Jesus E, Rothenberg G (2009) Palladium-catalysed telomerisation of isoprene with glycerol and polyethylene glycol a facile route to new terpene derivatives. 

On the other hand, the head-to-tail telomerisation of isoprene in the presence of diethylamine delivers N,N-diethylnerylamine in 85% yield and with high selectivity. 

CH2=CH(CH2)3CH=CHCH2NHCH0 and CH2=CH(CH2)3CH(NHCHO)CH=CH2 (83 17)S2i. Telomerisation of isoprene with cyclopentanone or cyclohexanone in the presence of H2O and Pd(0)/PR3 complexes gives the tail-to-tail products (57 n = 0, 1)S22 fhe arylation of activated alkenes with aryl chlorides catalysed by Pd(OAc)2/PR3 (R = Ph, p-MeCgH ) is accelerated by electron-withdrawing substituents in the aryl chlorideS23. 

The Pd-catalyzed telomerisation of 1,3-dienes (1,3-hutadiene, isoprene) with addition of a nucleophile (telogen) is a 100%-atom economical and versatile reaction that generates few waste and can he applied to a variety of bio-based substrates, including polyols, carbohydrates and sugar alcohols (Fig. 9). 5 jg attractive access to hio-hased hydrotropes. 

N-C bonds are broken by Pd catalysts in the telomerisation of butadiene with ally diethylamine to give mainly (47). The reaction of isoprene with HNEt2 in the presence of cationic Pd complexes gives mainly (50-70%) head-to-head telomers. Alkane- and arene sulphonamides react with butadiene like primary amines.Isoprene reacts with water (Pd catalyst, 90 0) to give a mixture of terpenols a catalyst supported on a phosphinated resin is prone to leaching. Butadiene reacts with cyclohexenone to give (48) in moderate yield. ... 

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