Enynes nucleophilic additions

In contrast to nucleophilic addition reactions to activated dienes (Sect. 4.2.1), the mechanism of 1,6-cuprate additions to acceptor-substituted enynes is quite well understood, largely thanks to kinetic and NMR spectroscopic investigations [3oj. 

Enynes (77) can react with arylboronic acids in the presence of a catalytic amount of a rhodium(I) complex under mild conditions to give (Z)-l-(l-arylethyl- (g) idene)-2-vinylcyclopentanes (78).100 In analogy, the rhodium-catalysed cyclization of the cyano-substituted alkynes (79) with arylboronic acids has been reported to produce the cyclic ketone (80) as the first example of a nucleophilic addition of an Rh(I) species to a cyano group.101... 

Activation of the triple bond of enynes with electrophilic metal derivatives, especially cationic gold complexes, platinum salts such as PtCl2, and ruthenium derivatives, has been reviewed.117 These catalysts make possible nucleophilic addition of the double... 

Krause, N. Zelder, C. Nucleophilic Additions to Dienes, Enynes and Polyenes. In The Chemistry of Dienes and Polyenes Rappoport, Z., Ed. ... 

Propargylic ethers are allylated by allyltrimethylsilane in the presence of the blend SnCl4-ZnCl2 (Eq. 86) [122], Thus acetals can be transformed to 1,5-enynes in one pot with sequential nucleophilic additions. The blend also catalyzes the allylation of aldehydes by allyltrimethylsilane, yielding homoallylic alcohols in good yields (61-74 %). 

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