Reaction with Carbon Nucleophiles and Homologs

l-Metalla-l,3-hexadien-5-ynes by Insertion of Electron-Rich Alkynes into the M=C Bond of a (l-Alkynyl)carbene Complex 

Insertion of an alkyne into the M = C bond of compound 1 may proceed in two different modes that lead to different compounds, depending upon 

1-MetaIIa-l,3,5-trienes M = C—C=C—C=C play a pivotal role in many applications of carbene complexes to organic synthesis. These compounds are readily available from methylcarbene complexes (by condensation, e.g. with a,/3-unsaturated aldehydes), from 1-metalladienes (by insertion of an 

Conjugated 2-alkoxy-6-amino-l-metalla-l,3,5-hexatrienes of type M= C(OR) — C=C—C=C(NR2) are most easily accessible by addition of enamines to alkoxy(l-alkynyl)carbene complexes in a broad array of different substituents. Due to the highly unsaturated character of such compounds a variety of transformations into organic products can be anticipated. Since 

Other than l-metalla-l,3,5-trienes M=C—C=C C=C, cross-conjugated metallatrienes M=C—C( = C) —C=C do not contain a conjugated 6tt system. There are several ways to generate such compounds, one of which involves metathesis of a C = C bond of an electron-rich alkene at the C=C bond of a (l-alkynyl)carbene complex. 

---