Multiple bond systems extended

Copper-mediated Addition and Substitution Reactions of Extended Multiple Bond Systems... 

As far as substrates are concerned, while the usual 1,4-addition and 1,3-substi-tution (Sn2 ) reactions of simple unsaturated substrates have so far predominated, analogous transformations of ambident substrates with extended multiple bond systems (i.e., with two or more reactive positions) have come to attention only recently. Here, systematic investigations have shown that such 1,5-substitutions and even 1,6- and 1,8-addition reactions proceed highly regioselectively and ste-reoselectively, in particular when the substrate contains at least one triple bond besides one or more conjugated double bonds. These unusual reaction types not... 

Krause, N. Hoffmann-Roder, A. Copper-mediated Addition and Substitution Reactions of Extended Multiple Bond Systems. In Modem Organocopper Chemistry, Krause, N., Ed. Wiley-VCH Weinheim, 2002 pp 145-166. 

Tissot M, Li H, Alexakis A (2014) Copper-catalyzed asymmetric conjugate addition and allylic substitution of organometallic reagents to extended multiple-bond systems. In Alexakis A, Krause N, Woodward S (eds) Copper catalyzed asymmetric synthesis. Wiley-VCH, Weinheim, pp 69-84... 

Note Added in Proof This is nicely illustrated by the landmark publication of Protasiewicz et al. [94] who describe derivative (122), the first conjugated polymers featuring phosphorus-phosphorus multiple bonds (Scheme 33). The di-phosphene-PPV (122) exhibits an extended 71-conjugated system as shown by the optical HOMO-LUMO gap that is close to that of related PPV [94]. 

---